Forensic Science

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Read the CSI Handbook. Available here: https://www.ncjrs.gov/pdffiles1/nij/178280.pdf 

and Read Chapter 4 in your textbook.

Summarize these readings. What information was most surpising or interesting to you? What do you know now that you did not know prior to reading these? Do you think the procedures for collecting forensic evidence are reasonable? Difficult? Why do you think rules are in place for collection?

Provide a list of psychological and legal terms you used at the bottom of your post


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“It’s not what you know, it’s what you can prove in court.” This is the coined phrase many individuals understand as the very bare minimum of evidence collection within the justice system. Although the reading in chapter four and the supplementary material explaining the procedures goes into a little more detail on how bias, contamination, trace evidence, and the roles of the defense and prosecution come into play during evidence collection; that phrase still holds as the basic understanding. Chapter four then went into the basic concepts of trace evidence from hair, body fluids, handwriting, and of course fingerprints and DNA. Although I had a basic understanding of each category the chapter explained well several problems faced with each category under the broad header of “forensic evidence.” The first as the book explained is the broad problem of Bias, contamination, and the structure of the justice system. Firstly, the book lead on, that those things which seem in their own right solid pieces of evidence such as hairs, and hand writing are often very hard to prove and ‘match’ in terms of a crime. The book explains this as the cognitive bias effect. This term is what I found to be most interesting within the chapter. Often time’s people remember the importance of preserving a crime scene in order to eventually find a causal relationship (if it exists between the crime and the perpetrator) but bias usually goes unnoticed. I myself had a basic understanding of the bias which occurs between the prosecution and defense (as that each side wants evidence for themselves) which then leads the defense having to play catch up in terms of the validity of the examination. This the book coined as a sub-category under the cognitive bias, known as ‘confirmation bias’, were an observer of fingerprints for example may lead to different conclusions if the examiner already knew that the defendant admitted to the crime or so forth. This then lead in to a better understanding of the article detailing how, and why techniques in evaluation, and collecting evidence is so important. When evaluating evidence it’s always important to use the “common sense rule.” And the process of collection is important to eliminate not only contamination, but to further strengthen the possible correlation between the perpetrator and the victim. This is why I think although very elaborate, the rules are needed. This is because as the book points out, just because all the evidence was properly handled does not mean all bias had been removed due to human error, observer’s opinion, and probability. As a result because proving something in terms of a causal relationship is so difficult, it’s very important that the collection procedure is followed strictly, so that when it reaches an evaluation state conclusions are not made based on false positives, due to the fact that the evaluation of that evidence is already difficult due to weak scientific foundations during examination, bias, and trying to communicate a “match” to jurors and so forth.

Terms: bias, trace evidence, contamination, defense/prosecutor, cognitive bias, confirmation bias, false positives.

Chapter 4: The Psychology of Forensic Identification
This chapter begins taking about forensic science (collection, analysis, and interpretation of physical evidence) and identification (linking physical evidence to an individual). It explains how it is nearly impossible to commit a crime without leaving behind some kind of evidence; a shoe print, finger print, tire mark, piece of fabric from clothes, blood/other DNA. The first technique of identification was called anthropometry (required measuring 11 items on the body. This was invented by Alphonse Bertillon. Next came modern day identification of biometrics (measurable anatomical traits to identify an individual).
Next, chapter 4 discusses trace evidence (evidence left at the crime scene and evidence transported from the crime scene.) If the two match it is said to come from a common source, which makes it a source attribution. The source then needs to match the trace, this is very difficult because there are many ways evidence can be obscured. There also needs to be similarity between the trace and the source, and there are four ways of expressing the similarities. Qualitative statement (non-statistical statement that indicates the strength of the match, i.e. weak, moderate, or strong) Simple match (non-statistical statement, says trace and source share similar characteristics) match plus statistics (statistical statement that shares how rare or common a particular match characteristic is relevant to the population) and individuation (Stating that a trace found at a crime scene came from a particular source). It then goes on to talk about how important reliability and validity are to an investigation.
Next, we learn about forensic identification. How DNA is made up and how individualized it is. Fingerprints, how there are loop, whorl, and arch patterns. Also how confirmation bias (search out evidence to support belief and ignore evidence that contradicts them)might affect forensic identifications.
Then the chapter discusses how on can reduce error and bias. This can be done through blind (examiner given no indication of correct results before or during testing)and double blind (examiner and test subjects do not know control group/correct identification until the testing is over)experiments. It also exclaims how science can help with the problem of identification bias. This is done by collecting data and calculating methods that minimize bias and being cautious of overgeneralizing their findings. Scientists trust in data and not bias.

Terms: Forensic Science, Forensic Identification, DNA, Anthropometry, Biometrics, Trace Evidence, Source Attribution, Qualitative Statement, Simple Match, Match Plus Statistics, Individuation, Reliability, Validity, Confirmation Bias, Blind, Double Blind

I really enjoy the field of forensic science, so this chapter and the CSI handbook were very interesting to me. In summary, the chapter talked about a wide variety of things investigators use to determine who committed the crime. The things I found most interesting were the sections on DNA, fingerprints (comparing latent prints to those of the perpetrator's), and tools (the idea that each tool leaves behind it’s own microscopic pattern or striation). All of these things add up to a very interesting and complex criminal investigation.
The CSI handbook complemented this chapter by going over the procedure that officers are to follow. I found it interesting that there are so many small, meticulous steps involved with the initial crime scene assessment. These are important, though, because I know that any little evidence lost could prove to be a huge setback for investigators.
The interesting things I learned from these readings were actually pretty common sense, minor crime scene things, yet they are stuff you’d never really think to do. The CSI handbook talked about not adjusting the thermostat or opening/closing windows in a crime scene (duh!) but it’s something you’ve never thought about before. Also, you should not let any initial witnesses/bystanders/suspects that were at the scene of the crime use the telephone or bathroom. It seems like common sense, but it’s actually a very important thing to remember.
I definitely think these evidence collection procedures are reasonable. When entering this field, you should know that this job will be very detail oriented and meticulous. I feel that these minor little steps are vital to get all the evidence you can from a crime scene. Yes, they may be a little difficult, and I’m sure they’re boring at times, but all investigators know that these steps are absolutely necessary. I believe these rules are in place so officers correctly know how to collect evidence, and so the contamination of evidence occurs as rarely as possible.

Key Terms: DNA, Latent Prints, Striations

This chapter explained the practice of forensic science, that is using evidence that has been collected from a crime scene and interpreted. Everywhere we go, we leave some kind of mark of our presence. The criminal justice systems uses this to its advantage. Forensic identification can be used to link a suspect to a crime with evidence such as a shoe print, DNA, fingerprints, marks from a specific tool, or fibers. When forensic scientists find a match, it is called source attribution. There are different ways in which scientist categorize the matches that they find which include making qualitative statements about the strength of the match, simply saying whether or not there is a match, making a match plus statistics statement, and individualization (saying that the match is so clear that it could have only come from one person.

Finding these matches is not as easy as it may seem. The media sways our understanding of this field far more than we like to admit to ourselves. Our authors mentioned that forensic labs are often poorly funded and backed up. It takes time to runs tests on all of the data that has been collected. Results are not produced in seconds and are also not always conclusive. A lot of factors can determine whether or not a clear, concise match will be found; a fingerprint could be smudged or not be in any criminal database. On shows like CSI, we see the computer spit out the results almost every time, but computers in the actual criminal justice system can only help narrow down the search. An actual person has to make the final judgement on the match. These crime shows’ portrayal of the area of forensic science oftens makes juries feel as though there is always going to be conclusive forensic evidence that can be used.

One of the problems with forensic science is that it is difficult to eliminate bias. The story at the beginning of the chapter helps capture just that. We often fall victim to confirmation bias, that is, only recognizing information that agrees with our beliefs. Another issue is the lack of reliability. In one study the authors discusses, few examiners were able to make the same match they had previously. Both of these issues can be tied back to psychology. We study biases and assess the implications that they can have on research, as well as social interactions. When examiners see gory pictures of the crime scene or has knowledge of the suspect’s background, race, or religion. The aspects of sensation, perception, cognitive, and social psychology are all present. Just as we discussed in class today, examiners must collect, interpret, and pass judgement on the evidence they come across.

I found the use of anthropometry to be very interesting. Examiners used the measurements of different parts of the body to identify individuals, because it was thought that the combination would be unique. Psychometrics was once used as well. In this field, examiners took measure of things such as reaction to sound or light, reaction time, and cranium size. Another thing I find incredibly interesting--and not necessarily in a good way--is how inconclusive the field of forensic science truly is. The authors mentioned several times that false positives and other errors are sometimes This is scary! Regulation of forensic science hopefully provides some guidelines for what can actually be used in investigations. The handbook outlined some of the rules set down for criminal investigators.

Terms: forensic science, evidence, forensic identification, source attribution, individualization, qualitative statement, confirmation bias, reliability, anthropometry, and psychometrics

Chapter 4 was a very interesting chapter to read and I feel like I learned a lot of interesting things. The chapter begins discussing the use of the term “match” and how it is used in law. The terms reliability and validity are described. A feature on DNA is next and the chapter says that this is the most widely used and most valid form of identification used today. An interesting section on fingerprints was next and terms describing fingerprints (friction ridges, latent prints, etc) were defined. The chapter also discussed psychological biases that go along with fingerprinting. More techniques were described that have weak forms of identification such as bite marks and tool identification. The chapter then went on to describing how to reduce error and bias (using double blind and blind tests).


The CSI Handbook was very interesting to read as well and basically discussed the proper procedures investigators and other personnel involved with the crime scene should follow. The handbook is broken down into different sections with headings such as “Arriving at the scene: initial response/prioritization of efforts; Preliminary documentation and evaluation of the scene; Processing the scene; Completing and recording the crime scene investigation; and Crime scene equipment.”


I was surprised by many things in reading these two things. First, I was very surprised at how shaky DNA and fingerprinting can be. Like many other people, I’m sure, I naively believed that these were very accurate measures of identification. It’s shocking and scary to think how many mistakes may be made based on “probability” in DNA. Moreover, it’s scary to think that someone may be sent to prison based on a half of a finger print! I was also surprised by the biases that finger print analysts tended to show in the studies described in the textbook. With the CSI handbook, I was first surprised how recent the handbook actually is (1998-1999). I was also shocked with how difficult it must be for investigators not to contaminate a crime scene while simultaneously worrying about those who need medical attention and showing compassion to victims and family members. I also had never thought of worrying about things out of your control such as rain, snow, etc. In addition, it was kind of shocking to read about the documentation process because I feel like when we see crime scenes on television, we are never shown this part of their job. Sometimes photographing is shown but scenes with paperwork are too boring to show to an audience. Another thing that surprised me was that investigators actually should have a systematic way of searching the crime scene for evidence. Once again, on television it basically looks like a bunch of investigators rummaging through whatever they find. Lastly, I was very surprised by how many items were listed that are required by investigators to bring to a crime scene!


I do believe the procedures in place are reasonable AND difficult. Obviously as someone with absolutely no training, it’s hard for me to believe investigators are expected to do all of the procedures listed with absolutely no mistakes. There seems like there’s so many things to think of when doing a crime scene investigation. I can’t imagine the types of psychological problems some of these crime scene investigators could be facing since they deal with huge amount of stress every day. I believe rules are in place for collection because otherwise it would be utter chaos. The crime scene would more than likely get contaminated easily and evidence could be lost along the way. This could easily snowball and we could have many wrongly imprisoned individuals with criminals out in the world on the loose. This procedural handbook seems very important to the legal system, psychology, and society.


Terms: match, reliability, validity, DNA, finger printing, friction ridges, latent prints, psychological biases, blind and double blind tests

Forensic Identification when speaking in terms of legal psychology is framed in this chapter as something important in order to rightfully convict a perpetrator. It is the process of linking a piece of physical trace evidence to an individual, usually a suspect to a crime. The chapter tells us that is virtually impossible not to leave any trace evidence (physical evidence left or transported from the scene of a crime) behind. There were two major forms of gathering such evidence; Anthropometry and Biometrics. Anthropometry was the first technique considered scientific. Using Anthropometry required eleven measurements of various body parts such as cranium size, arm length and others. This technique was later overcome by the fingerprint technology but was used for more than two decades before that. Biometrics, which was pioneered after Anthropometry, facilitated the system by which we identify evidence by using measurable anatomical traits or distinctive patterns in a person’s fingerprint, voice, iris, retina or face. Source attribution links trace evidence from the crime scene to the individual that committed the crime. It is the term used to indicate the two forms of evidence (samples from the crime scene and samples from the suspect) came from a common source. Once you have established a common source you then can say that you have an inclusion or match. Irrevocably, this means that there no differences among the samples that substantially would say otherwise. Comparably, individuation is an even better form of the conclusion that a trace found at a crime scene matches a source. Individuation excludes all other sources in the world (AKA I am 110% positive this is a match). Describing the extent to a match can be difficult for scientists; they have to describe the nature and certainty of a match to a jury and a judge. There are different types of testimony that scientists can use; a qualitative statement, simple match, or match plus statistics. Qualitative statements are somewhat personally biased statements explaining if a match is strong or not. A simple match approach is also somewhat biased in that the expert simply explains whether the trace and the source share certain class characteristics (intentional, recurring characteristics).A more detailed approach, the match plus statistics approach, involve statistics that give information about how common or uncommon a specific matching characteristic is. Anytime you look at statistics however, you naturally need to look at the reliability and validity of that measure to see how the researchers are getting their numbers. Reliability refers to the consistency of a measure and that validity of a measure refers to the fact that a measure measuring what it’s supposed to measure. Reliability can be very subjective while validity generally objective. One objective form of identification discussed in the chapter was DNA. DNA carries the genetic instructions for all living things. Therefore each living thing has their own individual DNA patterns which makes it a very individual-specific identification system; great for trace evidence. Fingerprints are another objective (to an extent) way to identify people. There are various types of fingerprints; loops, whorls, and archs. These different types, while no two fingerprints are exactly alike, hold similarities. Fingerprints along with many forensic identification techniques are only objective to an extent. Psychologically, the interpretation of such evidence lies in the hands of people and as psychologists we all know people are likely to let their cognitive biases influence the identification process. We will often work along a confirmation bias and search out evidence that confirms our beliefs and ignore evidence that contradicts them. We can reduce the likelihood that this will occur by conducting a blind or a double blind study. In a blind study the subjects are unaware that they are involved in a study or they don’t know which group they are in (controlled or experimental) nor do they know what the hypothesis is. In a double blind study neither the subject nor the experimenter knows which subjects are in the control group and which are in the experimental group.
The CSI handbook coupled the chapter really well in that it further went to explain exact procedure when arriving, evaluating, processing, and recording a crime scene. I didn’t realize the precise nature to which all of this happens but it makes sense. Crime scene investigation is a tricky thing and you only have one chance to do it right.
Terms: Perpetrator, trace evidence, convict, suspect, crime, anthropometry, biometrics, fingerprint, traits, source attribution, inclusion, individuation, qualitative statement, simple match, match plus statistics, biased, class characteristic, reliability, validity, subjective, objective, DNA, cognitive bias, conformation bias, blind study, double blind study, hypothesis, control group, experimental group.

The first link was from the U.S. Department of Justice, Office of Justice Programs specifically the National Institute of Justice. It is a guide as to the recommended practices for crime scene investigations although it would differ from jurisdiction to jurisdiction. There were five main points covered in the handbook which I found very informative: arriving at the scene, preliminary documentation and evaluation of the scene, processing the scene, completing & recording the crime scene investigation and finally, the crime scene equipment. I also enjoyed the glossary at the end and throughout the handout it would point out which words were in the glossary if the reader needed clarification. What I found surprising was how simple the steps seem yet the process is very complex. All of the procedures and steps are in place for the crime scene management process to be successful. There are devastating situations and sometimes chemical threats where certain collection procedures have to be in place. I just had not realized before reading this document how extensive the whole process really is. It is truly a very complex process and nothing is left unturned. Investigators have a lot more responsibilities than I originally thought. There are a lot of observations going on and many things that need to be assessed so that in the future there is evidence of the findings through photography or notes in general. After reading this very lengthy document I do in fact agree with the steps and procedures in place to help make sure a crime scene investigation is done properly and to the fullest extent documented.

Now Chapter 4 was a whole other ball game of information. It dealt with the psychology of forensic identifiers like DNA, fingerprints and the physical aspects/traces of evidence. I really liked this chapter and gained handfuls of knowledge from it. I have always been interested in the forensics of all cases but especially in criminal proceedings. I was very interested in how it whether directly or indirectly the first link is to our books Chapter 4. What I mean is the handout or guide from the above website stemmed from the research study and publication of the “Convicted by Juries, Exonerated by Science: Case Studies in the Use of DNA Evidence to Establish Innocence after Trial”. As a result of that publication the NIJ initiated the Technical Working Group on Crime Scene Investigation to create that guide with recommended practices for crime scene management. Chapter 4 is a complete dissection of what forensics really means. I really enjoyed learning the official terms used in forensics like psychometrics – the measurement of psychological characteristics. And what those tiny circles on your fingertips and hands are called friction ridges. The most surprising thing to me was the psychological biases in fingerprint identification? As well as how jurors think about trace evidence, which I did not realize it was also very complex. From taking into consideration the detailed information but also having statistical statements and other evidence presented at trial to assign identification evidence appropriate weight on their ultimate decision in a case. Finally, understanding that the goal of a forensic scientist is to find evidence that could have come from one and only one person and for a forensic psychologist it is just as important of a goal.

Most definitely all these steps are necessary and need to be in place. Yes, they are difficult and sometimes very difficult to control the circumstances of some situations – it is imperative that guidelines such as there are, are in place for the protection of the evidence and for the courts to prosecute in a justified manner.

Terms: Justice, courts, prosecute, crime scene, investigations, jurisdiction, scene, preliminary documentation, evaluation, evidence, recordings, crime scene equipment, devastating situations, chemical threats, collections, investigators, forensic, DNA, fingerprints, traces of evidence, case studies, juries, trial, psychometrics, forensic psychologist, friction ridges, statistical statements.

Chapter four of the “Forensic and Legal Psychology” book was very interesting. What I found most interesting about it was when it talked about how forensic science isn’t always 100% positive. The story that the book starts out with is about a series of bombings that took place in Madrid during 2004. The police in Madrid found a van that was filled with blue bags that were full of explosives. They were able to get some fingerprints from the bag and sent them to the United States for further analysis. The labs in the United States came back with the finding that the prints matched “100%” to Brandon Mayfield. Brandon Mayfield was a Muslim as well as a lawyer. He was arrested after two other “experts” agreed with the findings that the print found on the blue bags matched Brandon Mayfield 100%. However, it was later found out that it wasn’t Brandon who did it, in fact, a Spanish police officer even said that the prints didn’t have a 100% match before they even arrested Brandon Mayfield. However, this wasn’t enough to stop them from arresting him. This brings to question the reliability of forensic science. It also calls into question some psychology. The process that the police used in the story above was called Forensic identification. Forensic Identification is the process of linking evidence left at the crime scene to an individual. This evidence could be fingerprints, sperm, or hairs. After investigators get this information, they then use it in court to prove to the jury that that specific individual was the one to commit the crime. However, this method can cause some problem. One of these problems is called the “CSI Effect.” What the CSI Effect is that everyone has this idea of forensic science being 100% correct. This can lead to Jurors putting too much creditability with expert testimony of forensic evidence. This leads to another problem, people can be persuaded to think different things with how the information was presented. The book gives the example where both of the facts are the same; however, they way in which they are presented give the prosecution/defense the upper hand. This leads to Exemplar-cuing theory, where one of the two facts presented makes the jury think one way or the other. This was all information that I found interested in Chapter four. Before reading this chapter, I didn’t really have any background information on forensic science, however, it was a very interesting chapter and I learned a lot. I think that the procedure for collecting forensic evidence will improve as the science improves. There is only so much police can do when trying to solve a crime. Forensic science has come a long way, from starting with the anthropometry study, to DNA evidence. The reason that we have so many rules about how we collect Forensic Evidence is because we don’t want to put the wrong person in prison. When it comes to high profile crimes, a person could be spending a lot of time in prison. We want to put the right person in prison.

The PDF file was a very interesting read as well. The thing that I found most interesting about it was the procedures that are taken to make sure that the crime scene is not disturbed. The text itself talks about how they want to make sure “minimal contamination” happens to the crime scene. Before reading this PDF, I really had no clue how forensic science really worked. However, it was very interesting to see all the steps that the police take in making sure to preserve a crime scene. Another thing that I found interesting was the amount of different steps that were taken to prevent contamination. The PDF goes into detail on how to walk through a crime scene as well as explaining how to document different information. This different information that I am talking about includes things such as the exit door of the crime scene as well as the final survey of the crime scene. After reading this PDF, I have to say that the amount of information and detail that the forensic team takes to make sure that a crime scene isn’t contaminated is astounding. There is some much attention to detail, it really says to me that they want to make sure that they get the right person for the crime as well as not miss a thing at the crime scene. I think that the process is rather difficult; however, that is a good thing. If there are so many different things that a police officer has to do to make sure they don’t miss anything at the crime scene, they are doing a good job. The reason that I think that there are so many rules in place for investigators is as said above, to make sure that they put the right person in prison.

Terms Used: contamination, DNA evidence, anthropometry, Exemplar-cuing theory, CSI Effect, Forensic identification, psychology, forensic science

Chapter four of the “Forensic and Legal Psychology” book was very interesting. What I found most interesting about it was when it talked about how forensic science isn’t always 100% positive. The story that the book starts out with is about a series of bombings that took place in Madrid during 2004. The police in Madrid found a van that was filled with blue bags that were full of explosives. They were able to get some fingerprints from the bag and sent them to the United States for further analysis. The labs in the United States came back with the finding that the prints matched “100%” to Brandon Mayfield. Brandon Mayfield was a Muslim as well as a lawyer. He was arrested after two other “experts” agreed with the findings that the print found on the blue bags matched Brandon Mayfield 100%. However, it was later found out that it wasn’t Brandon who did it, in fact, a Spanish police officer even said that the prints didn’t have a 100% match before they even arrested Brandon Mayfield. However, this wasn’t enough to stop them from arresting him. This brings to question the reliability of forensic science. It also calls into question some psychology. The process that the police used in the story above was called Forensic identification. Forensic Identification is the process of linking evidence left at the crime scene to an individual. This evidence could be fingerprints, sperm, or hairs. After investigators get this information, they then use it in court to prove to the jury that that specific individual was the one to commit the crime. However, this method can cause some problem. One of these problems is called the “CSI Effect.” What the CSI Effect is that everyone has this idea of forensic science being 100% correct. This can lead to Jurors putting too much creditability with expert testimony of forensic evidence. This leads to another problem, people can be persuaded to think different things with how the information was presented. The book gives the example where both of the facts are the same; however, they way in which they are presented give the prosecution/defense the upper hand. This leads to Exemplar-cuing theory, where one of the two facts presented makes the jury think one way or the other. This was all information that I found interested in Chapter four. Before reading this chapter, I didn’t really have any background information on forensic science, however, it was a very interesting chapter and I learned a lot. I think that the procedure for collecting forensic evidence will improve as the science improves. There is only so much police can do when trying to solve a crime. Forensic science has come a long way, from starting with the anthropometry study, to DNA evidence. The reason that we have so many rules about how we collect Forensic Evidence is because we don’t want to put the wrong person in prison. When it comes to high profile crimes, a person could be spending a lot of time in prison. We want to put the right person in prison.

The PDF file was a very interesting read as well. The thing that I found most interesting about it was the procedures that are taken to make sure that the crime scene is not disturbed. The text itself talks about how they want to make sure “minimal contamination” happens to the crime scene. Before reading this PDF, I really had no clue how forensic science really worked. However, it was very interesting to see all the steps that the police take in making sure to preserve a crime scene. Another thing that I found interesting was the amount of different steps that were taken to prevent contamination. The PDF goes into detail on how to walk through a crime scene as well as explaining how to document different information. This different information that I am talking about includes things such as the exit door of the crime scene as well as the final survey of the crime scene. After reading this PDF, I have to say that the amount of information and detail that the forensic team takes to make sure that a crime scene isn’t contaminated is astounding. There is some much attention to detail, it really says to me that they want to make sure that they get the right person for the crime as well as not miss a thing at the crime scene. I think that the process is rather difficult; however, that is a good thing. If there are so many different things that a police officer has to do to make sure they don’t miss anything at the crime scene, they are doing a good job. The reason that I think that there are so many rules in place for investigators is as said above, to make sure that they put the right person in prison.

Terms Used: contamination, DNA evidence, anthropometry, Exemplar-cuing theory, CSI Effect, Forensic identification, psychology, forensic science

Chapter four begins talking about trace evident in context, which means evidence that is found and how it traced to a person or in most cases the criminal. First off, we must know that the definition of forensic science is defined as the collection, analysis and interpretation of physical evidence. But forensic evidence is different, because it is the process of linking a piece of physical evidence to an individual, or in most cases the criminal. The evidence could be something such as blood, hair, semen, and skin cells, which all could be confirmed through DNA identification. Or it could be something such as prints from a car, a piece from a shoe, or something else left behind at a crime scene. We can identify a piece of evidence to a person through anthropometry. Anthropometry is the way of identification which includes measurements of different suspects’ arm, finger, foot, leg and cranium. The meaning of measurement in forensic identification includes trace evidence the evidence found to possibly be linked to a criminal, source attribution when two samples appear to be similar, inclusion or when two matches seem to be the correct choice, and individualization which expresses the conclusion that a trace from the crime scene came from the source and not from the rest of the world. However, if all of the evidence does not link to each other or seem related, that would be considered to be excluded from the source, and if evidence is contaminated or impossible to link to a criminal is considered inconclusive. Identifying what a trace “match” source is difficult. Identifying a bullet can be difficult, along with handwriting and unusual such as materials in the crime scene like spackle, certain foods, or things on the wall or floor that would make it hard to identify hand or foot prints. Communication when referring to the similarity of a trace and or a source is difficult. A quantitative statement describes the strength or a source, weak or strong with the statistical evidence, and describes it in that manner to the court. Another approach is a simple match that does not make use of statistical evidence but looks at certain class characteristics that are consistent. A match plus statistic incorporates statements that place more into context, such as rare hair color and shoe size. Reliability refers to the consistent or repeatability of a measure or observation. Test-retest reliability measures how close the results are over a long period of time. Interrater reliability is the degree in which two or more observers or analysts independently arrive at the same measurement, or in other way two different people get similar results or finders. Measurement validity tells if the experiment or technique measures what it is supposed to measure. DNA is one of the bases for forensic identification. When scientists look at DNA they look for the alleles or loci on the DNA for similarities so they can identify the criminal. In order to tell differences and similarities and a person’s DNA. The random match probabilities or RMP’s refers to the calculated estimates that DNA will match samples from the crime scene. Fingerprints are another way of identification. Psychometrics or the measurement of psychological characteristics, and now we match using physical characteristics. When looking at handprints and fingerprints, scientists look at friction ridges on palms, and latent prints, or hand/fingerprints found at the crime scene. crime scene and the minutiae, or the features of them. A person who compares and analyzes these is called a ridgeologist. The one dissimilarity doctrines deals with a fingerprint with complications, and this idea that no identification will be made if a single unexplained dissimilarity in two prints is discovered. There are some biases in identification. Some of these include a confirmation bias, or an inclination to search out evidence that contradicts beliefs. A way to reduce error and bias would be to do a blind experiment or double blind experiment, so you can get unbiased errorless results. Finally, the way evidence is presented makes a difference. You should say something to a jury that fits with the side you are on, and make it “prosecution-friendly” and “defense-friendly”. Exemplar-cuing theory is a way of presenting evidence that makes evidence easier to understand.
The NCRJ handbook talks about crime scene investigation and the rules and procedures that must be followed when going through with an investigation. Some of this includes safety regulation, emergency care procedures, what people involved the scene should do, what to do with the evidence and all possible witnesses and suspects. This handbook is ultimate guide with details pertaining to everything that goes on at crime scenes, and what is done with the evidence and how it is properly documented. It is a great tool to see what all goes on at crime scenes and is interesting information to read about.

terms: forensic science, forensic evidence, DNA identification, Anthropometry, forensic identification, trace evidence, source attribution, inclusion, individualization, excluded, inconclusive, quantitative statement, simple match, match plus statistic, Reliability, Test-retest reliability, Interrater reliability, Measurement validity, DNA, alleles, loci, random match probabilities, Fingerprints, Psychometrics, friction ridges, latent
prints, minutiae, ridgeologist, one dissimilarity doctrines, confirmation bias, blind experiment,
double blind experiment, Exemplar-cuing theory

After looking through the CSI handbook, how I viewed the handbook after I was done skimming its contents is it is basically a handbook used in order to help make sure everything that goes on when a crime scene is created is under control and they have a very specific way of doing things. It is packed with policies and procedures to follow. It is good to know that they follow this handbook in order to be sure that everything is done properly. Especially after reading chapter 4 in our textbook, I now know how important it is that evidence is taken care of properly.
Chapter 4 in our textbook talked a lot about different procedures that can take place when looking at evidence, different problems with the procedures we use, and some different ways that we can steer clear of bias results or improper accusations. A few different ideas that stood out to me in chapter 4’s reading, that I didn’t really know or think about before were: the fear of accusing the wrong person, how to exclude bias when determining a “match”, the importance of DNA, and scientists vs. practitioners of forensic science.
The whole time I was reading this chapter, I was thinking in my head “how many people do you think are accused of a crime, that actually were completely innocent?” One of the reasons I began to think this is because not a single technique we use to verify evidence is 100% accurate, and there are people sometimes making the decision whether or not the evidence is a “match.”
It talked also in the chapter about how bias opinion can get in the way of results. As well as wanting to “look good”. I liked the example they gave of when they did the double blind study. The person wasn’t aware they were being tested, and they were unaware of the outcomes of the results. I definitely believe that people could be bias about making the decision of whether or not the evidence matches. If you were told that someone admitted killing someone, you would probably be more likely to support the evidence that proves the person actually really did it.
Something I learned that I didn’t know before is how DNA results are not always 100% accurate. That is why it is very important like I mentioned earlier that the crime scene is taken care of in the proper way, so that evidence is not contaminated, and therefore the best results can be found.
Lastly, one of the things that stood out to me was when they talked in the chapter about the difference between how much education a scientist goes through which is usually a PhD program, and a practitioner of forensic science which usually holds a bachelor’s degree. With this is states “Without elaborate graduate training, nonscientific values-such as pleasing one’s superiors- are likely to take priority over scientific integrity (Castanzo & Krauss).”
I believe the procedures they use to look at evidence have come a long way, but they definitely still have some work that could be done to insure even more validity and reliability. It seems highly difficult to examine such evidence, and I definitely don’t think I would be able to do what those analysts do. There has to be rules in place for collection or there would be even more biases then there already are.
Terms: validity, reliability, DNA, double blind, evidence, match, CSI handbook, practitioners of forensic science

The chapter talked mainly about the procedures that forensic scientists do at crime scenes and what kind of evidence is taken into account. You may have seen this on many different shows such as, CSI and NCIS that show a glimpse of what takes place after a crime is committed. At crime scenes there are witnesses and maybe even suspects at the crime scene the initial responding officer needs to take in all the surroundings before they start doing their work and collection of evidence. All bystanders, witnesses, and maybe even suspects are not allowed to leave the crime scene even to go to the bathroom. Evidence can be anything from a fingerprint, blood, handwriting, or even a cigarette holding a person’s DNA. Wherever you go, you leave some form of trace behind that says you were there, it is forensics job to find that something that could solve a case. That is why it is so important for people working at the scene to be careful what they touch and move they do not want to tamper with evidence.
The collection of evidence is taken to labs, which are not as glamorous or as high-tech as you see on TV. CSI shows that the lab equipment can have a finger print placed into the machine and they will get a name and face with that print every time, what they do not tell you or show you is that this is a long process and something that does not just happen immediately after the print is founded. The book talks about trace evidence and how the evidence found at the crime scene needs to match the evidence taken from the crime scene. If they do match they have a common source, finding the matching trace is the difficult part because so many things can be covered up or hidden at the crime scene. In the handout it talks about how careful people need to be when first coming to a crime scene and only absolute necessary people are allowed actually inside the closed off area. This is to prevent the evidence from being messed with by different peoples footprints and or fibers on their clothing that may throw investigators off. Medical personnel are only allowed in the crime scene if there is a victim that is injured at needs to be transported, even then the victim needs to be accompanied by an officer in case the victim says anything that needs to be documented for evidence. Medical personnel are to be very careful to not cut off or tamper too much with clothing where knife marks or bullet holes would are present.
There are many difficulties within forensic science, one being bias’s. Confirmation bias is said to be a huge issue because you want to prove your assumption or data correct so anything that you find that would support it is going to become of greater validity to you. Finding a fingerprint and thinking that you know it is already the person that law enforcement has in custody when that may not be the case at all. Keeping a clear and unbiased head in this field is very difficult because of all that is going on around you. Humans experience some form of confirmation bias everyday, if you have a thought or idea you think is valid, anything that is even close to backing it up is reliable information to you. It is common human and error. It is pretty crazy all the steps that someone has to go through when first coming to a crime scene and how one thing that goes wrong can make everything domino effect after that.

Terms: Forensic science, evidence, validity, reliability, Confirmation bias, DNA, fingerprinting, Trace, Source, and Source Attribution.

The first reading was about the policies dictating a crime scene. What to do, how to do it, and what not to do. Basically a SOP for crime scenes. Chapter 4 went into different forms of evidence and talked about the validity of them. It seems that DNA evidence is pretty accurate, while other forms of evidence is not as accurate as people tend to think.
I wasn’t really surprised or shocked at the standards that went along with checking a crime scene. A lot of the things done had the same feel the military has. Granted every crime scene is different, but basic rules apply and at first you might be shaky on them but after a few crime scenes things just get to be automatic. However from a behavioural psychology standpoint there are many things that can affect this. If you are tired, depressed, irritated, etc. then the quality of your job can majorly be effected, and you can easily forget things that shouldn’t have been forgotten. For example in clearing a room there have been times where my mind wasn’t exactly on the job and you forget crucial things. It’s a good thing nothing came out of mistakes like that, but it easily could have. Same thing can be said of a crime scene if one person makes a mistake then it can jeapordize the whole case.
Some things that were surprising in the reading was a lot in Chapter 4. Everyone has watched CSI and other shows like that, and while I knew that a lot of that was fake and unrealistic this chapter proves that it was much further than I thought. I remember doing mock trial in highschool and basically a lot of the evidence they use in mock trial (all cases are based of real trials) I now found out that with a bit of research you could basically discredit it. I remember specifically a handwriting expert as a witness, and with the chapter learned that was essentially false. And then most of the evidence entered by experts are left up to their discretion, or for a better word, opinion. They used the example of most people that do fingerprint evidence changed their opinions years down the road. Stuff like that can mess up a trial very badly. Now one part of me wants to say that unless you show me conclusive evidence then I wouldn’t find someone guilty however the only really strong evidence to me is DNA, and if that wasn’t offered then I would have a hard time convicting someone. However most cases cant provide that evidence and their might be other semi-strong evidence that would support that case.
To me psychologically there are so many factors that jurors have to consider it makes their job very difficult. They have to decide if an expert is actually qualified to give an expert opinion. If the chances of error are low with that opinon. Then they have biases that could affect them at any time of the trial. Even though they try to weed those out before the trial they may still exist. Then if someone messed up at the crimescene everything could be found as false. There just seems to be too many forms of error in deciding if someone is guilty or not, that I would have a hard time being a juror knowing all of it.
Ultimately I find the procedure to collect evidence pretty satisfactory, however, it is still very easy for someone to make an error in that process. And that makes the job of investigators and police very difficult. And these sops are in place so mistakes can be minimized.

Terms, Psychology, Behavioral psychology, Evidence, Juror, DNA, experts, witness, case, investigators, police, crimescene, sops, opinion, discredit, error,

"One of the most important aspects of securing the crime scene is to preserve the scene with minimal contamination." Both the chapter out of the book and the Crime Scene Investigation handout preach this philosophy heavily. It makes sense from both a law and psychological standpoint because the crime scene is most vulnerable when the police force, FBI, and citizens are poking around. The chapter in the book was more of an overview at how evidence is taken from a crime scene and entered into the database to determine potential suspects. One example used in the book was a man suspected of being behind bombings in Spain. His left index finger matched one of the prints pulled from a van containing bombs and he was immediately "trailed" by the FBI. It brought about an important psychological aspect of confirmation bias. Because of this man's spouse and his recent conversion to Islam he was targeted as a prime suspect even though only one of his finger prints matched ones pulled at the crime scene. The FBI ignored twenty other potential suspects because of his background.

This introduces the topic of reliability and validity. From a legal stand point and because of the vastness of the fingerprint database federal officials have to use, identifying someone as a suspect because of a fingerprint match still remains one of the most valid measurements around. Although, as in the case of the bombings, the FBI can make it as reliable as they see fit. In that particular case because the accused man was not the perpetrator it was not a reliable measurement to draw conclusions from.

The PDF document on proper crime scene investigation etiquette was useful because it gave detailed instructions on how to prevent the crime scene from becoming contaminated or even worse inconclusive. When I was reading the document I kept thinking about the movie Se7en and how Morgan Freeman and Brad Pitt would arrive at repulsive crime scenes and use forensic identification to look for clues. Also as a reader of the Hardy Boys when I was younger it brought back some memorable moments from those detective novels. I can imagine from the perspective of an officer first arriving at a crime scene it could be nerve racking trying to prevent unauthorized persons from entering the crime scene or handing the duties over to higher personnel when your men were their first. It becomes second nature for those people to view any scene as a crime scene. For example, do they enter a church and see the priest and fellow followers, or a room full of clues?

Terms: confirmation bias, validity, reliability, fingerprinting, inconclusive, forensic identification

To have or not to have is the big question here. It is either you have the proof and the evidence behind the criminal act. Having proof and evidence are the biggest deciders in a court ruling, as long as the evidence supports your explanation and fits the crime you should be good. This chapter gives the major details about the forensic aspect of crimes and how big of role evidence, reliability, and statements play in the ruling of a criminal case.

Chapter four goes into detail about various finger prints, types of finger prints such as; loops, whorls, and archs that one’s finger print might have. When finger prints are found on a surface they are called latent prints and that is what most forensic scientist look at. Another thing the forensic scientists look at is the DNA that is found at the crime scene to find the criminal. Whether it be semen, blood, hair follicles, or saliva.

The CSI Handbook goes into talking about what you should do if you find a crime scene that looks very important and how you should act. When you find something that looks like a crazy crime scene you should call for emergency technicians who know what they are doing and try not to contaminate evidence as much as possible, this can easily mess up findings that could be used in court. It also talks about transferring over the crime scene to the emergency crew and how they document everything that was found on the scene.

Honestly I think the whole CSI Handbook was interesting to me, it caught my attention right away and most things do not do that. What I did not know before this reading was the fact that how much teamwork is actually involved and how many people are working together to get one scene cleaned up and figured out.

I think that the procedures for collecting the forensic evidence are quite reasonable but also at the same time quite difficult. They have so many people working at the same site at one time that it would be hard not to contaminate anything around you with your own footprints or hair follicles. It gets crazy sometimes. I think rules are in place for the collection of the evidence because if there weren’t any rules things would get out of hand. Things have to be done a certain way for things to actually be used in court. You can’t just go in somewhere that has been said to be a crime scene and pull apart things and pick at things because you would probably ruin some of the evidence and it could never be used again, which that could have been a very important piece of the missing puzzle.

Key Terms: Evidence, reliability, statements, loop, whorl, arch, latent prints, DNA, CSI Handbook, contamination

Chapter 4 talks about forensic science and how scientists and everyone in the legal system go about examining evidence found at a crime scene. Evidence that has been found such as DNA, fingerprints, bullet striations, etc. are considered trace evidence. Crime scene traces are compared to other samples, and if the sample matches, the scientist has made a source attribution. When trace evidence has been found, it must somehow be explained to a jury. I found this part interesting because I had always thought of fingerprints and DNA as being a match or not a match. I didn’t realize that the evidence can be expressed as a simple match (the trace and source share the same characteristics) and as a match plus statistics (describing the match in a more statistical approach). I also found it interesting that when DNA evidence is found, there is the chance that it could have occurred by chance alone. This is called a random match probability. In comparing law with psychology, I found a link between how evidence is presented to a jury, and then how the jury decides to use that evidence. To me, this is a link between law and social psychology. For example, it has been shown that jurors have difficulty making sense of statistical statements, and the exemplar-cuing theory has that jurors are more likely to listen to a statement of evidence if there are more examples and if the statement is easier to understand in lamens terms. This shows that it is imperative to clarify the meanings of statements, so that the evidence can be processed as non-biased as possible.

The second document was very interesting because it was a step-by-step guide on what the first officers on the scene should do, all the way through to explaining how the forensic evidence should be collected, transported, and processed. I found that it was very detailed and easy to understand, there didn’t seem to be any room for confusion because each step was so clearly stated. If evidence was processed by this booklet alone, I feel that there would be no problems in solving a case, but as the book states, there are surrounding factors that can come up during the investigation.
I think that the procedures for collecting and recording the evidence are clear and reasonable, but I believe what makes investigating difficult is human error and the fact that people can be biased to believe in a certain way. Therefore, I believe that rules are in place so to lessen the chance of human error and biases, so that an investigation and trial may be as fair and accurate as possible.
Terms: social psychology, DNA, fingerprints, evidence, probability, jury, bias, trace evidence, trail, crime scene

The CSI handbook was all about gathering and preserving evidence for law enforcement. The handbook starts out with a brief introduction on what it should be used for and how it is not a working model for every crime scene investigation. Each case and scene is unique and the author’s want officers who read this handbook to be reminded about that. The introduction also emphasizes that jurisdictions should ask for help, more training, more funding, or partner up with other jurisdictions if they cannot follow the procedures well enough to get the job done. The introduction also directs officers where to go or who to contact if they need more information or are dealing with different types of cases, like arson or chemical threats. In the background section of the handbook it describes where this consistent approach to crime scenes came from. Attorney General Janet Reno asked the National Institute of Justice (NIJ) to study cases where convicted sex offenders were exonerated of the crimes from the use of DNA testing, which resulted in the NIJ publishing a book. NIJ was then asked to create the consistent process that is used today. The NIJ established an 11-member planning panel, the National Crime Scene Planning Panel, which then had the task of choosing candidate for the Technical Working Group on Crime Scene Investigation (TWGCSI). There was a criterion for each candidate to meet and 44 people, who were considered experts in their field, were invited to TWGSCI. At a later date in 1998, a guide format was created for the TWGCSI to follow, the guide needed to have a statement of principle, a statement of policy, a procedure, and a summary. The drafts were then sent to a wider audience for overlook and corrections, then revisited and edited, and then published in 1999. The handbook consists of five sections.
The first section is Arriving at the Scene: Initial Response/Prioritization of Efforts. Each section has multiple sub-topics, which all have a principle, a policy, and a procedure to follow. The first subtopic is the initial response, the second subtopic is about safety procedures, the third subtopic is emergency care, the fourth subtopic deals with securing and controlling people at the scene, the fifth subtopic deals with setting up and placing boundaries. The second section is the Preliminary Documentation and Evaluation of the Scene. This section of the book also includes subtopics. The subtopics include conduct scene assessment and conducting scene walk-throughs and initial documentation. The third topic is Processing the Scene, which includes topics on Determining team composition, contamination control, documentation, prioritizing the collection of evidence, and collecting, preserving, inventory, packaging, transporting, and submitting evidence. The fourth topic is Completing and Recording the Crime Scene Investigation. This section includes establishing crime scene debriefing teams, performing final survey of the crime scene and documentation of the crime scene.
The handbook then has a section Crime Scene Equipment, which includes three sections. The first is for the initial responding officers and includes things like first-aid kits, cameras, chalk, and flashlights. The second is for crimes scene investigators and evidence technicians, which includes things like biohazard bags, body fluid collection kids, disinfectant, tool kids, mirrors, magnifying glass, and phone listings. The third section is for evidence collection kits and has examples, like for blood, fingerprints, and impressions.
I personally think that the procedures in this handbook for collecting evidence is reasonable, all of the people involved in these processes’ are experts and should know what they are doing and should be able to do an extremely thorough job. The time we live in depends a lot on DNA and recordings and hard evidence to convict in the judicial system so it is pertinent that crime scene investigators do their jobs to the best of their ability and live up to the standard that this handbook sets for them.
Chapter four of the book discusses forensic identification and begins with the long search it took for people to positively identify some sort of evidence to a certain defendant. The first system used was anthropometry and included eleven different measurements on a person to identify them; this was used for about two decades but was abandoned when the use of fingerprinting emerged. The text goes on to explain that trace evidence left at the crime scene includes fingerprints, fluids, hair, etc., and that trace evidence transported from the scene includes hair, fibers, blood. When evidence is collected and given to a scientist they can determine if things match, finding source attribution, or believing something is individuation. A scientist can also determine if things do not match or if evidence has been contaminated. The text goes on to discuss how sometimes traces do not match their sources and how things like matching bullets are no longer acceptable ways to match a source, along with handwriting, and how sometimes rare or unusual things happen to things fingerprints and footprints that make it hard for a scientist to create a match.
The text describes communicating similarities of traces and sources in four different ways. The approaches include qualitative statements, simple matching, match plus statistics, and individuation. Then it discusses measuring reliability and validity and then to the foundations of forensic identification. This includes DNA, the patterns that are unique to individuals, the DNA in blood and semen and skin, and how DNA corresponds to different people and how it can result in a perfect match but sometimes an imperfect one. Fingerprints are another foundation of forensic identification and are widely used. Fingerprints are collected using powders, tapes, lights, and magnification because the friction ridges in the latent prints are hard for the naked eye to see. Fingerprints are usually matched by comparing the ridges but that can be up for interpretation by any individual and are usually believed to be up to the trained examiner.
The chapter goes on to discuss bias in collecting and interpreting evidence. This is important because it determines how matches are made and why errors happen. The solution proposed by the text is using science, although it can still occur by someone choosing to ignore evidence. The text discusses peer reviews as a way to keep personal biases in check and also try to keep financial interests in check when things are at odds. The text ends by discussing how jurors look at forensic evidence and how they interpret things. The authors find that there is evidence that many jurors cannot correctly interpret evidence and findings and also read statistical information differently, which can greatly affect the outcome of trials.
The information that was most surprising to me and something that I did not previously know was in the beginning of this chapter about the first methods of identification. It is amazing how far things have come and how little scientific evidence was actually used in the past. From reading both the chapter and the CSI handbook I think that all of these rules and processes are used to keep punishing guilty people and keep innocent people out of jail. It is important in our society to have an efficient and correct penal system, which starts with the people gathering evidence and interpreting them correctly.

Terms: evidence, bias, trace evidence, fingerprinting, individuation, validity, forensic identification, forensic science, anthropometry, witness, defendant, victim, ridges, chemical threats, crime scene, penal system, crime scene investigation

Chapter 4 discusses several interesting concepts that have been translated in movies and TV shows. One of my favorite shows to watch is CSI; I have always thought they were very interesting. However there are several aspects that are not expressed correctly for example, It is not as easy as the actors make it look when collecting evidence and analyzing fingerprints. As stated in the book forensic science is defined as the collection, analysis, and interpretation of physical evidence. Forensic identification is the process of linking a piece of physical evidence to an individual. The overall goal of individuals who work in this field is to have proof that will stand in court and eventually result in a conviction. Through the years several techniques have been used, changed, and nor used anymore due to it not being a valid and reliable test. For example the first test used was called anthropometry. This technique involved taking 11 measurements and it was used for a long time until analyzing fingerprints came about. Overall forensic science and identification process have changed and developed to ensure more accurate results.

When gathering evidence at a crime scene comparison between two samples typically occurs. The first sample may include fingerprints, hair, and skin cells this is called trace evidence. The second sample is evidence that is transported from the crime scene such as carpet fibers. Forensic scientists then analyze the samples to decide if they are a match. As stated in the book if the two samples match each other they are said to have come from a common source and the scientist is said to have made source attribution. This process is very important as if any of the evidence is contaminated it will not stand in court, and thus may allow the perpetrator to be free.

A very important idea involving whether or not we trust our measurement in regards to evidence is reliability and validity. Scientists want their tests to be reliable and valid so they are able to trust the results they analyze. Reliability refers to the consistency or repeatability of a measure or observation. And validity refers to whether or not a technique measure what is supposed to measure. If a test is reliable and valid it is viewed as valuable and trustable information that can be used in court.

An interesting concept from the text discusses the analysis of DNA in shows like CSI and how it is actually done in real life. On TV shows we see the “scientist” collect DNA and put it in a machine and a second later the screen says “match.” It is not this easy in real life to analyze DNA. Scientists like to see every allele match because that is a clear identification compared to when DNA test yield ambiguous results. When this occurs scientists calculate the probability that two profiles match, this test is called random math probabilities. Overall DNA is an extremely important aspect when it comes to identification but it is not as easy to analyze as it appears on TV.

One thing that I did not know before reading the text is that fingerprinting only narrows down a group of possible people. I thought every fingerprint was unique and only one person could be found in the computer system. What ends up happening is that an examiner sorts through the possible matches and makes the final judgment on whose print it is. When fingerprints are found on a surface at a crime scene they are referred to as latent prints. Scientists gather the print for analysis by using powders, special lights, and magnification because they are hard to see.

Gathering forensic evidence from a crime scene is not as easy as TV crime shows make it look. There is a lot of room for error to occur, which in turn impacts the end result of who gets sentenced. I think it is good that rules are in place and that individuals who work in this field go through a lot of training. As if there are any mistakes the evidence can be thrown out of the case and no longer used in proving who committed the crime. It is also important to think about if any biases occur when analysis of the evidence occurs. For example if the scientists wants the fingerprint to prove that a specific individual was at the crime scene, they may analyzed the print differently and possibly cause them to choose the wrong individual. Overall the text and the CSI hand book explained several aspect involving analysis of evidence as well as who analyzes. I found these readings to contain a lot of information that I previously did not know or realize.

Terms: forensic science, forensic identification, anthropometry, trace evidence, source attribution, reliability, validity, random match probabilities, DNA, fingerprints, latent prints.

These two readings were very interesting to me, I have always been a fan of crime shows and curious as to how close they were to real life. What I found out is that some things as exact and some are pretty far off. A few things I already knew, like documenting evidence, and securing the crime scene. What I didn’t realize is how much equipment CSIs have to have with them at all times. You never know what you’re going to run into, and have to be prepared for everything. In regards to chapter four, there was a lot that I wasn’t aware of. The fact that struck me the most was that there is no telling whether there are no two matching fingerprints. I realized that there were common types, but I always figured they were a little bit different. I also didn’t know the what the term latent print meant, I knew that they used it in crime scenes but for some reason I always thought it was only a little bit of a finger print, what it really means is that it’s a fingerprint that you cants see with the naked eye. I was also amazed at how much trace evidence people leave behind without even thinking about it, if you scratch your head, cut yourself on a glass, anything can leave behind evidence. One final thing I found interesting was that the people running tests would make them blind or double blind. I always knew about blind and double blind studies but I had never thought about them in regards to crime, but now that I know the information it only makes sense.


Terms:
Latent print
Trace evidence
Blind
Double blind

Chapter 4 talks about various methods of forensic identification. It begins by discussing various methods of identification that were used in the past as evidence. These include methods such as anthropometry, fingerprinting, and DNA testing. The chapter states that usually forensic identification rests on a comparison between two samples, which are generally trace evidence of some sort (fingerprints, hair, clothing fiber, blood, etc.) and a second sample taken from a subject that is being questioned. The chapter spends time explaining how tests used for comparison of samples are done and why it is important that they be accurate. Tests need to be reliable, with test-retest reliability being important in DNA comparisons as an example and interrater reliability being important in things like witness testimony. Tests must also be valid in order for their measurements to be trusted enough to be used in a trial. I feel that the testing processes and the importance put reliability and validity draw a good comparison to how research is done in psychology. The chapter then spends more time explaining the various methods of forensic identification, talking about DNA testing and explaining further in the process and history of fingerprinting. While discussing fingerprinting, the chapter mentions Sir Francis Galton, an early psychologist and pioneer in the field of psychometrics, which is the measurement of psychological characteristics. I had learned about Galton in other psychology courses but there was certain information in these few paragraphs that I hadn’t seen discussed before. No other class had ever gone into a good explanation of things such as Galton’s method of classifying fingerprints. After explaining fingerprinting, the book discusses the importance of reducing error and bias in the various methods discussed previously. It stresses the importance of using methods such as double blind studies to reduce various forms of bias. This is a very important concept in conducting research in psychology and it makes sense that it is equally important in this field as well.

For the most part, this chapter was a review and expansion to various things I was already aware of in the legal system, forensics, and scientific methods of study. It helped to expand upon most of these as well and was a very interesting chapter to read. Something that I wasn’t aware of was that DNA evidence and fingerprints can be unreliable. Fingerprints make more sense in retrospect but I always assumed that DNA was almost perfectly reliable.

The CSI Handbook explained a bit more in-depth about various guidelines and standards for collecting and analyzing evidence. I feel that it is a good complement to the chapter and gives a better explanation than the book on how actual forensic officers are to conduct themselves while collecting evidence. It was nice to see that the process is fairly simple to follow and that much of it is based on common sense. I feel the way it is broken up into sections makes it a good, useful handbook that even a layman could use appropriately.

Overall, I feel that the methods for collecting, analyzing, using forensic evidence are as reasonable as they can be while maintaining the standard for accuracy that they need to have. Although they may be difficult at times, I feel that the primary importance is the accuracy of the measurement in order to prevent wrongful convictions. I am glad to see that there are important guidelines in the field of forensic evidence which help prevent its misuse.

Terms: forensic identification, trace evidence, anthropometry, fingerprints, interrater reliability, reliability, test-retest reliability, validity, Galton, double blind, error, bias, DNA

This chapter discusses the reliability of different types of trace evidence that is recovered from crime scenes. Trace evidence can include hair, skin cells, fingerprints, other forms of DNA, etc… This evidence is interpreted and compared to other samples by specialists to identify suspects or perpetrators of a crime. When a researcher claims the 2 samples “match”, or inclusion, he or she is said to have made a source attribution or has found the trace comes from the same source. In contrast, if the 2 samples do not come from the same source, the evidence is inconclusive.
Several types of trace evidence have taken several decades to finally be recognized in the legal system as credible support in a case. One type is called deoxyribonucleic acid (DNA). Discovered in 1953, by James Watson and Francis Crick, DNA is the genetic instructions for all living cells within a certain human. Each human being has their own DNA combinations consisting of different alleles. An allele is the genetic material for different characteristics. The largest database for DNA is called the Combined DNA Index System (CODIS). This catalog will narrow down other DNA samples that are similar to the trace evidence researchers are looking for. Once the databank has narrowed the search results, an analyst must make the final call on a matching sample. After an additional 30 years, scientists finally rediscovered the potential of this type of evidence. People vs. Wesley in 1988 was the first time DNA was used in the U.S. Court system.
The next type of evidence is fingerprints. Discovered in 1892, Sir Francis Galton forged the way on counting similar points of interest (loops, whorls, and arches) in fingerprints. Fingerprints are made up friction ridges, tiny lines that create designs on both the palms of your hands and your fingertips. This use of evidence was quickly used in the legal system and courts. This type of trace is very difficult to convict someone with. Like CODIS, the fingerprint database can only narrow down potential matches. A ridgeologist will then compare the similar samples and claim that they are inconclusive or inclusion. These researchers have to been relicensed/reviewed every year. It is important to have an analyst who is not biased toward any suspect in particular. Another reason why fingerprints may not be enough evidence to convict someone can be due to the print quality or very similar characteristics of a suspect to the actual trace print. Researchers are unsure if the once popular “No 2 fingerprints are the same” statement is actually true.
The Crime Scene Investigation: A Guide for Law Enforcement is a small book outlining the proper procedures for everything from being the first responder to collecting evidence and recording evidence. This book was made specifically for law enforcement officials and other first responders. The individual chapters go through important procedures in which could lead to the conviction of the perpetrator instead of a suspect.
Something I was very surprised about was how long it took DNA to be found useful in court trials. I was also very surprised to learn all the crime scene shows that I have grown up with, were not completely correct. I have always known that they were never totally 100% correct, but it was interesting to learn what parts were right and which were wrong. I now know that the computer does not do all the work in finding matches to DNA or to fingerprints. I also now know most analysts do not have all of the proper education they should have to determine things about evidence. I think the rules are reasonable because I feel that the evidence is one of the most important things in convicting the perpetrator(s). I wholeheartedly believe there are innocent people in prison due to not collecting or mishandling of evidence. The book also states it is not intended for strict use, but as an outline of the events/procedures.

Key Terms: reliability, trace evidence, inclusion, source attribution, inconclusive, DNA, allele, CODIS, fingerprints, loop, whorl, arch, friction ridges, ridgeologist

Chapter 4 in our textbook starts off by discussing forensic science and forensic identification. The book defines forensic science as the collection, analysis, and interpretation of physical evidence and forensic identification as the process of linking as piece of physical trace evidence to an individual, usually a criminal suspect. Both of these terms come into play simply because it is nearly impossible to commit a crime without leaving some sort of physical trace behind. It then goes on to discuss when a trace “matches” a source. They use the example of trying to match bullets that have been used to bullets that may be in the possession of a suspect. They also talk about handwriting analysis (a form of pseudoscience). They conclude that a main complication in matching a trace to a source is that many cases require conclusions about rare events and unusual materials. This will require research and experiments to be done in order to gain the knowledge needed in order to match things correctly. There is also a section that is covered that I have a lot of experience with due to previous classes. They discuss reliability and validity. They define reliability as the consistency or repeatability of a measure or observation. There are two different kinds of reliability: test-retest and interrater. They define validity as whether or not a technique measures what it is supposed to measure. These two definitions are obviously very important to psychology, but this chapter helps you understand how they can apply to psychology and law as well. This chapter also introduces DNA (deoxyribonucleic acid). It goes on to give smaller details about when and how DNA was discovered, but it also discusses how DNA evidence in court is very, very important. If the DNA from the crime scene corresponds with a suspect, then there is clearly a match and that person was present at the crime scene at some point. It also discusses how there are ways that DNA tests can yield ambiguous results. This can be due to poor quality of the DNA collected at the crime scene or contamination of the sample during handling and analysis. The chapter next introduces fingerprints. According to the chapter, fingerprints somewhat fall under the category of psychometrics (the measurement of psychological characteristics). The discovery of fingerprints and what they meant can be attributed to Sir Francis Galton when he decided to apply the interest he had in psychological characteristics to physical characteristics as well. A few different characteristics of fingerprints are friction ridges and latent prints. The last section of immediate importance in my opinion discussed how you are able to reduce error and bias. One way of doing so is to take advantage of routine retesting of traces in order to resolve and ambiguity about findings. Also, trying to make sure that the examiners that are working are as experienced and well-trained as possible is important. This will help avoid experimenter error.

The website for the CSI Handbook was very intriguing as well. It was quite lengthy, but it seems as if that is necessary for the amount of information they are trying to get across to the reader. I think it did a very good job with the ordering of the handbook. It started from the beginning of what should happen when you arrive and then moved to how you should actually collect the evidence and process the scene. I also liked how they talk about the different kinds of equipment that will be needed in order the process the scene. Again, it was lengthy but it had just the right amount of detail to inform someone of the proper procedures for crime scene investigation.

There was nothing in this chapter that necessarily surprised me, but I did rather enjoy reading the entire chapter. I have learned about some of this in previous classes, but I really liked the way that this chapter was put together. It made for an easy and interesting read.
An area that I was not as familiar with that I was able to expand on was the section on how jurors think about trace evidence. I guess I have never really thought about it from their point of view, even though their thoughts and ideas about these things are really what matter in the end.

I definitely think that the procedures for collecting evidence are reasonable. It may sound like a difficult and tedious job, but when collecting something related to a crime it is vital to be able to get the best evidence that you can. Contaminating or ruining evidence at the scene or in the lab can make or break a case. Sometimes the physical evidence that is collected at the scene is the only evidence there is for a trial. Having something happen to this evidence would be devastating. As stated before, it may be a difficult job but the task they are performing needs to be in the hands of people who are experienced and know what they are doing. People at this level should have no problem with the difficulty of the job. All of the previous explanations are exactly why rules are put into place as well. There needs to be some sort of organization and procedure for the people collecting physical evidence.

Key terms: forensic identification, reliability, validity, test-retest reliability, interrater reliability, DNA (deoxyribonucleic acid), psychometrics, friction ridges, latent prints

This chapter just confirmed what most of us already knew. There are flaws in our legal system and innocent people are in jail/prison as a result. The efforts of law enforcement aren’t to blame though. The field of forensic science has evolved greatly. For example, when identifying suspects people used a technique called anthropometry. This technique was a series of eleven measurements that included the left foot, length of the middle finger, length of the arm and so on. This form of identification was used for over two decades. Now, we use fingerprints to identify suspects. Even this isn’t 100% full proof, the Mayfield case is a prime example. There are certain steps and procedures that have been put in place to minimize possible errors that are outlined in the CSI Handbook.
This handbook goes through step by step what officers need to do from the first report of an incident to the final documentation of the crime scene. Throughout this handbook it emphasized the importance to minimize contamination at any cost. There are several minute details that often are over looked and/or damaged if this procedure within this handbook isn’t followed as closely as possible. Setting the boundaries of the crime scene would probably be one of the hardest tasks an officer would have. They have to determine possible routes that the suspect could have left the scene, where the incident may have started and ended and numerous other variables. Because of these variables a lot of the decisions made are up to the discretion of the initial officer on scene.
The handbook also goes through all of the equipment that is needed when examining a crime scene. It outlines the essential and optional equipment needed by initial officers and the crime scene investigator/Evidence technician. We hear in television about blood spatter, raising fingerprints and trajectory but the little bit of equipment that tv CSIs take along isn’t nearly enough to get the job done correctly. Television has began to create a problem within the legal system. There are now biases that are formed and also juries expect there to be large amounts of physical evidence found, when in reality there isn’t.

TERMS:
physical evidence
legal system
trajectory
crime scene
fingerprints
blood spatter
crime scene investigator/Evidence technician
discretion
suspect
forensic science
Mayfield case
anthropometry

I first looked at the CSI Handbook. The first thing I noticed was the date on the cover page: January 2000. It surprises me that such an important document of law enforcement has not been updated for over a decade. I read that the National Crime Scene Planning Panel and the Technical Working Group on Crime Scene Investigation were both selected in 1998. These groups were responsible for developing this guide for law enforcement to follow when investigating crime scenes. The guide was published in 2000, and to my knowledge, has not been updated. This really surprised me.

This handbook gives law enforcement a thorough idea of how to handle all aspects of a crime scene, including: arriving at a scene, preliminary documentation and evaluation of a scene, processing the scene, recording the crime scene investigation, and necessary crime scene equipment. Within each aspect, such as arriving at a scene, there are many steps. Each step has a principle, policy, procedure, and summary. It is extremely thorough, and somewhat repetitive. Reading through the specifics of arriving at a scene, I noticed that you are not to open any windows or doors. At first, I wondered what they are supposed to do if someone is still alive on the scene and is injured… but there is a note at the bottom of the section that reads: unless necessary for the safety and well-being of persons at the scene. As I said, this thing is extremely thorough.

There is also lots and lots of paperwork that has to be done. All evidence must be immediately photographed, documented, and collected as first observed at the scene. They also must do video, sketches, measurements, and additional notes of anything that could be used as evidence, which basically means everything. The official documentation of the crime scene includes everything of the entire investigation, and I can’t imagine how long this tedious process would take. We never see this step of investigation on movies, as it would be extremely boring.

Chapter four got into the details of forensic science and identification, from a psychology perspective. Forensic identification is the process of linking a piece of physical evidence to an individual. Biometrics is measuring anatomical traits to identify individual people, making it possible to link evidence to a suspect. This chapter talked a lot about how we gather evidence, trace “match” a source, and make sure it is reliable and valid. The chapter went on to describe DNA, which is the most widely used and most valid form of forensic identification. Fingerprints were discussed next, and I learned that common patterns are called: loops, whorls, and arches. There are some psychological biases when using fingerprint identification that we need to be aware of. The chapter talked about how to reduce biases when trying to find any matches between crime scene trace and individuals.

I think the procedures for collecting forensic evidence are reasonable, as well as difficult. It is hard to believe people can go through every procedure perfectly every single time. Crimes (especially involving victims) can be very emotional and stressful and it would be extremely difficult to look at crime scenes objectively in order to get all possible evidence. The book talked about a study dealing with psychological biases. When subjects saw emotionally arousing stimuli (like graphic crime scene photos), they were most likely to see two fingerprints as matching. There is obviously no perfect way to deal with this stuff, but I think the procedures have been put it place for a good reason. They give us the best possible systematic approach. We have to start somewhere, and I think knowledge of psychology can help us be aware of things like biases and catch as many mistakes as possible.

Terms: CSI Handbook, crime scene, preliminary documentation, principle, policy, procedure, evidence, forensic science, biometrics, DNA, fingerprints, loop, whorl, arch

I first looked at the CSI Handbook. The first thing I noticed was the date on the cover page: January 2000. It surprises me that such an important document of law enforcement has not been updated for over a decade. I read that the National Crime Scene Planning Panel and the Technical Working Group on Crime Scene Investigation were both selected in 1998. These groups were responsible for developing this guide for law enforcement to follow when investigating crime scenes. The guide was published in 2000, and to my knowledge, has not been updated. This really surprised me.

This handbook gives law enforcement a thorough idea of how to handle all aspects of a crime scene, including: arriving at a scene, preliminary documentation and evaluation of a scene, processing the scene, recording the crime scene investigation, and necessary crime scene equipment. Within each aspect, such as arriving at a scene, there are many steps. Each step has a principle, policy, procedure, and summary. It is extremely thorough, and somewhat repetitive. Reading through the specifics of arriving at a scene, I noticed that you are not to open any windows or doors. At first, I wondered what they are supposed to do if someone is still alive on the scene and is injured… but there is a note at the bottom of the section that reads: unless necessary for the safety and well-being of persons at the scene. As I said, this thing is extremely thorough.

There is also lots and lots of paperwork that has to be done. All evidence must be immediately photographed, documented, and collected as first observed at the scene. They also must do video, sketches, measurements, and additional notes of anything that could be used as evidence, which basically means everything. The official documentation of the crime scene includes everything of the entire investigation, and I can’t imagine how long this tedious process would take. We never see this step of investigation on movies, as it would be extremely boring.

Chapter four got into the details of forensic science and identification, from a psychology perspective. Forensic identification is the process of linking a piece of physical evidence to an individual. Biometrics is measuring anatomical traits to identify individual people, making it possible to link evidence to a suspect. This chapter talked a lot about how we gather evidence, trace “match” a source, and make sure it is reliable and valid. The chapter went on to describe DNA, which is the most widely used and most valid form of forensic identification. Fingerprints were discussed next, and I learned that common patterns are called: loops, whorls, and arches. There are some psychological biases when using fingerprint identification that we need to be aware of. The chapter talked about how to reduce biases when trying to find any matches between crime scene trace and individuals.

I think the procedures for collecting forensic evidence are reasonable, as well as difficult. It is hard to believe people can go through every procedure perfectly every single time. Crimes (especially involving victims) can be very emotional and stressful and it would be extremely difficult to look at crime scenes objectively in order to get all possible evidence. The book talked about a study dealing with psychological biases. When subjects saw emotionally arousing stimuli (like graphic crime scene photos), they were most likely to see two fingerprints as matching. There is obviously no perfect way to deal with this stuff, but I think the procedures have been put it place for a good reason. They give us the best possible systematic approach. We have to start somewhere, and I think knowledge of psychology can help us be aware of things like biases and catch as many mistakes as possible.

Terms: CSI Handbook, crime scene, preliminary documentation, principle, policy, procedure, evidence, forensic science, biometrics, DNA, fingerprints, loop, whorl, arch

The online reading is a manual that is published for the use and aid of officers and medical staff that respond to a crime scene situation. By reading the very first sections of the manual online, it is apparent that sensory psychology is a huge part of the initial response to the scene, as well as perception and cognitive psychology. The manual dictates that all officers need to be fully aware of any all conditions when first approaching the scene first in order to gain as much information about the nature of the incident as quickly as possible, and secondly so as not to disturb any of the potential evidence. It is also interesting the way the manual deals with the social psychology aspect of those who are on the scene. It dictates that all bystanders be removed, while all suspects and witnesses contained and separated, and that any family should be contained with compassion. This idea of treating all different roles of the crime in a different way could greatly skew how they view the criminal justice system based upon how the officers or medical officials treat them. Another intriguing point is that the manual completely avoids the problem of memory of the officers drawing sketches or filling out relevant paperwork by mandating that it happen while still on the scene. Imagine how often the evidence collected on a scene would be questioned and or misrepresented if the manual didn’t explain that those measures need to be taken while one is still physically present at the scene. The procedures set forth in this manual do seem to be a bit extensive, however it is easy to see why they are in place. Without something this through and simplified a lot of evidence would be lost and or contaminated beyond use. Another very important concept that I was surprised to see laid out in this manual were the search and seizure laws that need to be taken into account. In almost every section where evidence collection and preservation was concerned, the warning of obtaining a warrant showed up. The book chapter is about how understanding how biases in perception, judgment, and decision making can effect the legal system in some pretty big ways. The introduction to the chapter is an excellent example of this principle because due to the biases of those investigating the case, and their perceptions of the facts in front of them led them to believe that Mayfield was the one who had handled the bomb, even though this was disproven by authorities in Spain. Biopsychology could be applied to identifying perpetrators when physical evidence is concerned in that certain hormones or compositions of blood that may be known by physicians concerning a particular mental disease or simply as a matter of general record.

sensory psychology, perception, cognitive psychology, social psychology, search and seizure laws, biases, judgment, decision making, Biopsychology, physical evidence, hormones, mental disease

The CSI Handbook talked about what you should if you happen to see a crime scene. They gave different types of crime scene scenarios. For example, if you see one that seems as though it was spur of the moment you are recommended to call emergency services and let them handle the situation and how you are never supposed to contaminate the crime scene. When they come and you tell them what you know, saw, heard, etc. about the crime scene they take into account everything. They document the evidence that they see when they arrive and what you said.
It later then goes into detail of the process for collection, transportation, and processing the documented evidence. These processes were explained very clearly and if they go step by step, there shouldn’t be any problems. Although, I think that sometimes it can be fairly difficult because of human error as well as the amount of people that are documenting evidence at this one crime scene. Having too many people like that can cause a lot of human error. I think this is where a majority of issues start to occur. People let their bias views and beliefs get in the way of what’s right and what’s wrong. There’s no room for that in the legal system, it should be a yes or no and fact. Nothing should be in question if the evidence is right there; it’s a yes or no.
In Chapter 4,it gave a lot of terms and interesting information. What I found extremely interesting was the finger print information that I read. Everyone knows that no one’s two finger prints are alike. I mean there are types of finger prints, for example, majority of them kind of take a tear drop/swivel kind of shape. Yet, somehow there is not two that are alike. The term latent fingerprint I didn’t know about. I can remember hearing it on one of the many CSI TV shows I’ve watched. This term means that the fingerprint is not viewable to the naked eye. When they have to dust for fingerprints then the fingerprint becomes viewable. Another term I was unaware of was anthropometry, I’d never heard of this term before. It’s used to describe the measurement of the size and proportions of the human body.
The chapter says that usually forensic identification rests upon comparison between two samples. These are typically trace evidence like blood, hair, and fibers; and a second sample taken from a subject that is being questioned (suspect). The book also talks about how the tests need to be reliable and valid. I’ve known these terms from previous courses on psychology. The most effective way to make sure a test is reliable is to use test-retest method in order to prove that reliability is occurring. The test must be valid for the measurements to be reliable enough to be used in a trial. I think that this could be seen as a correlation of psychology and law in order for them to be able to be used in court they must use a method that psychologist use in their research.

Terms: crime scene, contaminate, collection, transportation, processing, evidence, legal system, finger print, latent fingerprint, anthropometry, forensic identification, samples, trace evidence, fibers, suspect, reliable, valid, test-retest, trial, psychology, law, research.

After reading chapter four I lost a little bit of faith in the legal system and how defendants are convicted. I did not realize that there could be so much room for human error, either because of biases or by missing steps and the complexity of the procedures used stated in the CSI handbook. I just have always thought that fingerprints were indisputable evidence until I read this chapter, and a major problem with that is a lot of jurors think the same thing. I also had confidence that investigators had the knowledge to figure out what gun a bullet came from, until I read that 13 million bullets could all have the same chemical makeup, this does not narrow down the suspects at all. The fact that this evidence is used to convict somebody of a crime even when there is so much room for error appalls me. It leads people to believe that defendants are being tried fairly when in all honesty the evidence can sometimes be so high in error that the trial is not fair at all. I also found in interesting that attorneys can sway the jury by just how they word a fact. They can make it should to be more in favor of the defense of the prosecution, such as exemplar-cuing theory which states that the use of frequency in a statement, such as 1 in 100, makes it easier to imagine other people who might also be a match for the evidence then when an attorney uses a percentage.
Confirmation bias is also a big problem when trying to decipher evidence, and inclination to search out evidence that confirms our beliefs while ignoring evidence that contradicts them. This can cause issues when looking at finger prints or bite marks. If the examiner has it their head that the defendant has committed the crime then they will be more likely to find evidence supporting that, even if there is more evidence that disproves it. This kind of bias is not only found in the legal system but also in our everyday live. For example, when you have a negative opinion or positive opinion of someone you look for things that confirm that, like if they hold a door open for you of if a person passes by without saying high. These instances stick out in your mind rather than the ones that contradict your opinion. It can be hard to change an opinion once it is already there.
Unlike clinical psychologists who help people with mental problems that have to get their Ph.D., examiners rarely have to get much more than a bachelors. I find this very hypocritical. Both people are influencing the outcome of someone’s life greatly, but yet the level of knowledge and education they have are very different.

Terms: Clinical psychologist, confirmation bias, exemplar-cuing theory, fingerprints, CSI handbook, defendant, prosecution.

This chapter is about exploring forensic science, how it can have errors and they can be avoided. How to use evidence to find a suspect, anthropometry was used in the beginning until fingerprints became the new thing. It is also discussed how it is impossible to commit a crime and not leave a trace evidence. By using sample from a crime scene which is looked at as class identifications or individual identifications, a trace of evidence can be conducted. The section of the chapter that I found most interesting would be the Measures and Meaning in Forensic Identification part. The reason why I found this section to be most interesting to me because when wording something you have to be careful of how to phase it, one word could change the whole meaning, or a person’s perspective of their decision making. For example like jurors, if a scientist where trying to describe how the trace of evidence is accurate to the suspect and if the evidence was not 100% a match, if they were to word that so and so evidence is a match, the jurors would automatically think “the evidence fits there are guilty. But if they were to hear it is possible that the evidence came from the suspect, their thoughts are more open-minded like it could be the suspect or not. When reading about the fingerprints section, there was a part where they explained how on TV shows they usually find the fingerprints and process they fairly quickly and find the perpetrator. In real life however, when they dust for prints and find the latent prints, the minutiae which are the features of the prints it takes a while to process them, and if the prints aren’t in the database then the fingerprints are practically not useful. I think collecting Forensic evidence is reasonable but yet also difficult. Forensic identification can be helpful a lot of the time by taking fingerprints, or finding class or individual characteristics the only difficulty aspect I see is this process takes a while to attend to and sometimes it has errors. But not everything can be perfect we just have to assume it’s not always right and see that other evidence backs it up. I think that there are rules in place for collecting data because we want to make sure that the evidence it collected at caution so it is not contaminated, so there is a slighter chance of receiving a false positive. Forensic experts have to be cautions when handling the evidence and lean how to evaluate, process, and record the evidence.
Terms: Forensic science, Suspect, Anthropometry, Fingerprints, Trace of Evidence, Class Identification, Individual Identification, Perpetrator, Latent prints, Minutiae, Forensic Identification

In summation, both text described the process and details of forensic science and how it relates to crime scenes. I did think the textbook chapter focused more on how important validity and reliability are in forensic science. This type of science relay on trace analysis and attention to detail when collecting/processing data. The text chapter also discussed how DNA and fingerprints have had a huge impact on modern forensic science. In American history both DNA and fingerprints where not admissible in a court of law. It wasn't until recently science could prove both data types to be reliable and valid in criminal trials. This chapter also noted that forensic science and it's detailed process is constantly changing. What was not practical a decade ago is now more important than ever; likewise what is accepted in today's courts could easily be tossed aside for a number of reasons in the future.
The online CSI Guide was repetitive in some spots, to the text. However, the online text seemed to be more informative and regimented with protocol and procedure. It is an official document produced by the department of justice. If I was in charge of the investigation/patrol division of a department this would be a must read for every one of my officers and investigators. This document is a step by step walk through from the initial response to a crime scene all the way till the final debriefing investigation.
Prior to these reading I, like many others, have this Hollywood run and gun CSI image of what a crime scene looks like and how it is processed and completed in 3 hours. Obviously this is not the case. After these reading I now better understand that there is an enormous amount of time, effort, protocol, and procedure that goes into forensic science and a crime scene. I was apparent in both text that a key to this type of science is stopping contamination of the are and making sure all the evidence and data is valid enough to hold up in court; if that’s not the case than the data isn't worth collecting and presenting. This is a new perspective on crime scene investigation for me.
These procedures and protocol may seem a bit much but we must realize what these crime scene procedures are trying to accomplish. All of the attention to detail and making sure the evidence is reliable and valid all go back to one thing, Justice. This type of science is often essential to help solve a case and make sure Justice is served. In my opinion, we can't put a price tag or time limit on Justice. As soon as we start regulating and limiting Justice; injustice will be soon behind it. Ensuring the crime scene stays contained and uncontaminated is just as important as paying attention to detail, keeping records, and intake of evidence. The process may seem difficult but that is often the name of the game in any field of science or criminal justice for that matter. If being a forensic scientist or responding officer was easy everyone would be doing it. The amount of rules and protocol are necessary for such a detailed and important job. If the first steps of responding and controlling the crime scene fail then that whole investigation may fail. It all is in the manner of making sure that Justice is properly accounted for.

Chapter four in our textbook covers what forensic science is about and the tedious work it takes to gather evidence from a crime scene. A major portion of the chapter is about the task of fingerprinting suspects to determine if they are the one who committed the crime. What I found interesting in the readings is how it is said that no two fingerprints are alike in anyway, and so many people have had that idea engrained in their minds in the several decades of forensic science. In the example stated at the beginning of the chapter where Brandon Mayfield's prints were lift from the bag of explosives down at a crime scene in the subway system. It turned out he wasn't the one who committed any crime. So it just goes to show that fingerprinting can result in some error and an innocent man being wrongfully accused. Before fingerprinting sparked in the early 1900s, Anthropometry was used. It was the process of taking 11 different measurements of the human body to determine who committed a crime, but that was tossed out the window and fingerprinting came into play. This chapter explains how analysts try to find a ''mach" and the negative or positive effects it can have in the legal system. All though a lot of findings can be determined as a weak scientific foundation for many forms of trace evidence. They need to look tediously at all forms of trace evidence they find at crime scene. Trace evidence found at the crime scene and trace evidence transported from the scene which could be anything from blood, saliva, hair strands to carpet fibers or broken glass, most significantly... fingerprints. There are psychological biases when it comes to fingerprint identification. These biases are influenced more by cognitive biases. When it comes to identifying fingerprints, it becomes difficult to get the examiner's cooperation because it is such tedious work. Examiners really need to work to make their evidence reliable and valid to stand a strong ground in the legal system because one would not to be wrongfully accused. Reading through the CSI handbook I thought it was interesting to learn what guidelines examiners and investigators have to go through to accurately gather and secure evidence from a crime scene. I feel that the procedures for collecting evidence from a crime scene are good way about doing that work. Even though there are way more similarities in lifted fingerprints than people believe, it is still a more of a sure way to determine who the culprit is. DNA analyzing I think is more accurate because everyone has more uniqueness in their DNA codes. Sure this is tedious work but there are willing people out there who do it and actually enjoy it.

Key terms: Anthropometry, trace evidence, validity, credibility, reliability, cognitive, biases

I thought this was a very interesting chapter and I have always been interested in forensics and how DNA is used to convict people. Right off the bat in this chapter they had a story about the bombings in Madrid. This story was very interesting because it showed how several members of the FBI thought they were easily correct in their decision, but a police department in Spain found otherwise. This was interesting because it tells us that even DNA evidence can be mistaken by biases. This chapter spends a lot of time talking about forensic identification which is interesting because it is an important part in finding and prosecuting individuals in the court of law. It was also interesting to read about all of the ways we have, in the past, found forensic evidence against someone, and that later on the methods are found to be inaccurate and no longer supported by the criminal justice system. I thought it was interesting when they were talking about the handwriting experts and how between 40 and 97 percent of the time the experts make an error. It is disappointing thinking about how many possibly innocent people have been jailed due to these inaccurate evidences. I thought the approach of a simple match was interesting because it is the process of the trace and the source sharing certain characteristics. I thought it was interesting when they talked about measurement and validity because these terms are often discussed in psychology when thinking about a psychological study or treatments. It is important for the cases to be reliable so that the tests will be the same no matter who is giving it and who is taking it. It is also important for the test to have good validity. I thought it was interesting when they were talking about DNA. It is interesting how law enforcement can get DNA from almost anything. It is interesting how in some cases, depending on the quality of the DNA sample, the alleles in the DNA sample can match up exactly making it a clear match. I also thought it was interesting how if it is a poor DNA sample there can be random match probabilities. The section about biases in fingerprint identification was also interesting. I thought the study they did with the examiners and their previous confirmed prints was crazy. Depending on the context 4 out 5 examiners changed their previous statements. That means their must have been a pretty strong bias which makes me wonder how often the fingerprints are actually correctly matched without a bias getting in the way.
The CSI handbook was also interesting because it had a list of steps that need to be followed for crime scenes. It has very thorough directions for almost all aspects of handling the crime scenes. I found it interesting how much detail they put into this handbook. But it is important to have all directions so there is no confusion on what is supposed to be done. I found it interesting how it talked about how to handle evidence and make sure the crime scene isn't contaminated.
This was an interesting chapter and I learned a lot of things that I did not know before reading it. Learning about evidence and DNA were the most interesting things to me in this chapter.
Terms: bias, simple match, trace, source, measurement, validity, reliability, DNA, and RMP.

You can’t go through the channels on TV without seeing some who that have to deal with forensic science. The link and chapter four give a clear picture that what we see on TV isn’t how things are handled in real life. The link gives us guidelines of how law enforcement officers and CSIs handle certain crime scenes. I never knew there were so many things that officers should follow when coming up on a crime scene. Officers should always be paying attention to the smallest details and record everything they see at the scene. A “walk-through” is extremely important to the case because that when is important evidence is documented and photographed. The instigator in charge is responsible for so many things; he must conduct interviews of everybody around and be in charge of forensic specialists and crimes scene sketch artists. I didn’t realize that so many people were needed to investigate a single crimes scene. I also didn’t know that there were special containers for certain evidence such as porous, nonporous, and crushproof containers.
Chapter 4 beginning by giving examples of early identification processes and how it has improves over the years. The earliest examples include anthropometry and biometrics which both includes measuring the offender’s traits to identify them. It also talks about trace evidence to identify a suspect, through physical trace or possible by biological evidence. The four ways of connecting trace and source are very important to convicting a suspect of certain crimes. Qualitative statements are the simplest followed by simple match and match plus statistics. The fourth and final one is individuation, which the most important. With this trace the forensic scientist are almost hundred percent sure that the trace came from this person. DNA is the most important identification evidence, because everybody’s DNA is unique to each person. Fingerprints are also a great way to identify a suspect and connect them to the scene because no fingerprints are the same. I believe that reliability and validity are key to any investigation. Many departments will have many investigators on one case and multiple people test the evidence to make sure the finding is correct. Paperwork and documentation are very important to show how evidence is handled throughout the case. Bias can be a big problem with many investigations, because some evidence can be overlooked.
Key Words: DNA, Reliability, Validity, Forensic scientist, Forensic identification, trace evidence, biological evidence, physical trace evidence, porous, nonporous, crushproof, walk-through.



In summation, both text described the process and details of forensic science and how it relates to crime scenes. I did think the textbook chapter focused more on how important validity and reliability are in forensic science. This type of science relay on trace analysis and attention to detail when collecting/processing data. The text chapter also discussed how DNA and fingerprints have had a huge impact on modern forensic science. In American history both DNA and fingerprints where not admissible in a court of law. It wasn't until recently science could prove both data types to be reliable and valid in criminal trials. This chapter also noted that forensic science and it's detailed process is constantly changing. What was not practical a decade ago is now more important than ever; likewise what is accepted in today's courts could easily be tossed aside for a number of reasons in the future.
The online CSI Guide was repetitive in some spots, to the text. However, the online text seemed to be more informative and regimented with protocol and procedure. It is an official document produced by the department of justice. If I was in charge of the investigation/patrol division of a department this would be a must read for every one of my officers and investigators. This document is a step by step walk through from the initial response to a crime scene all the way till the final debriefing investigation.
Prior to these reading I, like many others, have this Hollywood run and gun CSI image of what a crime scene looks like and how it is processed and completed in 3 hours. Obviously this is not the case. After these reading I now better understand that there is an enormous amount of time, effort, protocol, and procedure that goes into forensic science and a crime scene. I was apparent in both text that a key to this type of science is stopping contamination of the are and making sure all the evidence and data is valid enough to hold up in court; if that’s not the case than the data isn't worth collecting and presenting. This is a new perspective on crime scene investigation for me.
These procedures and protocol may seem a bit much but we must realize what these crime scene procedures are trying to accomplish. All of the attention to detail and making sure the evidence is reliable and valid all go back to one thing, Justice. This type of science is often essential to help solve a case and make sure Justice is served. In my opinion, we can't put a price tag or time limit on Justice. As soon as we start regulating and limiting Justice; injustice will be soon behind it. Ensuring the crime scene stays contained and uncontaminated is just as important as paying attention to detail, keeping records, and intake of evidence. The process may seem difficult but that is often the name of the game in any field of science or criminal justice for that matter. If being a forensic scientist or responding officer was easy everyone would be doing it. The amount of rules and protocol are necessary for such a detailed and important job. If the first steps of responding and controlling the crime scene fail then that whole investigation may fail. It all is in the manner of making sure that Justice is properly accounted for.

Key Terms: Justice, law, police, CSI, case, protocol, procedures, evidence, department, debriefing, investigation, criminal, trials, courts, official, department of justice, trace analysis.

Chapter four starts off by telling us about the bombings of a Madrid subway that killed 191 people and injured 1460. The Spanish police ended up finding a mini-van with explosive evidence and they found fingerprints. They ended up finding a match or an inclusion of someone and started an investigation on him. He had his phone tapped, office secretly searched, found out everything about his life then. They found out that he was a lawyer and had been an attorney for someone that had ties with the Taliban. He seemed suspicious and with three FBI agents saying that he match the fingerprints, he was put on trial. He ended up not being the match with further review of the fingerprints and they arrested another man and this trial was over.

This is a prime example at how far technology has gone for the police and the FBI. They have the technology to find fingerprints on evidence and match it with someone out of millions of people. They use forensic identification which is the process of linking a piece of physical trace evidence to an individual, usually a criminal suspect. Although this technology is very high, it is not 100% reliable, but they are working on other ways to strengthen the validity. Fingerprint scans use the friction ridges on the fingers and a ridgeologist uses a holistic approach to compare prints. But going back to the case of Brandon Mayfield who's...how could they of had an %100 inclusion on this person, take him to trial, surveillance him and then find out that he actually is not the one that was involved in the bombings? Something is a little off with forensic identification. Looking at the CSI handbook, I saw that it was pretty much the handbook to how to solve a case. If I wanted to solve a crime and go on an investigation, I could look at this handbook...

Key Terms: forensic identification, friction ridges, inclusion, reliability, rideologists,

Chapter four talks about forensic science and the methods of obtaining evidence. It also gives examples of the errors and mistakes that take place in premier law enforcement agencies, such as the FBI. The chapter starts by explaining what forensic science is and what it is used for, which is using forensic identification to link evidence to a criminal suspect. There are also many ways to measure forensic identification. Some examples are trace evidence (left at the crime scene), source attribution (when 2 samples match each other), inclusion (similar and no differences), individuation (absolute match). Suspects may also be excluded, or if the evidence is contaminated the conclusion would be inconclusive. Analysts have do decide on the reliability and validity of tests. They can strengthen their confidence of these tests by doing a test-retest, in which they should come up with the same results time and time again.
It wasn’t until the discovery of DNA that forensic identification really took off with success. If DNA from a crime scene corresponds perfectly to a suspect’s DNA sample, there is obviously some match. Every allele must match, in which you would have clear finding. The use of fingerprints to identify people was also a great break though in the field of psychometrics (psychological characteristics). One problem with using analysts to identify similarities between prints is a bias notion when shown gruesome crime scene photos, which lead them to seeing to prints as matching. We can reduce these errors and biases by using tests that are blind (examiner is given no indication of the correct results), or even more effective, the test can be double blind (analyst doesn’t know he/she is being tested).
The courts use a great deal of forensic identification evidence. If they were to use only the most reliable evidence, the effort to increase the validity of forensic techniques would go up. There are certain techniques that the court still accepts that probably need to be refitted to be more suitable. This is all very important because it would diminish the number of wrongly accused and free the innocent who are incarcerated.
Before reading this chapter I had never heard of the “CSI Effect” which basically entails that there is always evidence left behind, ample time to conduct careful analyses in huge laboratories. These TV dramas are unrealistic and give people the wrong idea of forensic identification. It times a lot of time and effort to do the things that really goes on in forensic science. I also think that the procedures for collecting forensic evidence are complex and difficult. There are so many steps needed to cover a single piece of evidence that I feel too many conditions would overlap and get confusing. But that is why rules are in place during the collection because it gives a guideline on how to collect and what to do with the samples. It also makes for a fair trial. Defendants deserve a fair trial because they are innocent until proven guilty, and you can’t just assume someone’s guilt. Evidence doesn’t lie and I think forensic science will be around for pretty much eternity.

Terms: Forensic science, trace evidence, source attribution, inclusion, individuation, excluded, inconclusive, allele, DNA, reliability, validity, test-retest, psychometrics.

The first link on this weeks blog was for the CSI Handbook. It contained the proper steps and procedures when entering a crime scene. The first and most important step is to secure and preserve the crime scene with minimal contamination. In a court of law, physical evidence trumps almost anything, so it is important to maintain the integrity of the evidence. The next step is to control the physical threats of the crime scene and then provide or call for medical attention. Again, the book stresses the point minimal contamination. One thing I found interesting here is if you think a victim is mortally wounded you should try and get a dying declaration from them. I looked in the glossary and this means to try and get a statement from them about what happened or who did this to them. After these steps are done the next thing to do, according to the handbook, is to secure and control the persons at the scene and also set up boundaries of the crime scene. When other people arrive to take over you should give them control and brief them on what you know, and then document what happened so far. The next section in the handbook is over documenting and evaluating by conducting a crime scene assessment, walk through, and initial documentation. The next steps are over processing the evidence. Here you provide a contamination control while documenting and prioritizing the evidence before you inventory, package, transport, and submit it. The final section was over completion of the crime scene where the debriefing team performs a final survey and documentation.

Chapter 4 of our book covered the field of forensic science. It stated that forensic science is the collection, analysis, and interpretation of physical evidence. It also talked about identification, which is linking that physical evidence to an individual. We can measure this physical evidence with anthropometry, which is measuring eleven items on the body. A more modern method is with biometrics. These are measurable anatomical traits to identify an individual. This chapter also spoke of trace evidence, which is evidence left at the crime scene and evidence transported from the crime scene. It is important for these two to match so that the evidence is credible and can be used in court. The book spoke of four ways of expressing the similarities of the evidence. The first is through a qualitative statement, which expresses the strength of the similarity. The second is a simple match. This states if the trace and source evidence are similar or not. A match plus statistics states whether the match is rare or common in the population. The last is individuation, which states that it came from a particular source. The next section was over fingerprints and how they were characterized by loops, whorls, and arches. The final section was over biases such as experimenter bias, where the experimenter looks for evidence to support their ideas, and gives ways in which to counter these biases, such as a double-blind reading, so that the evidence is not contaminated and maintains its credibility.

The thing I found most interesting was the fingerprints. It amazes me how each individual has a different fingerprint and how we go about marking and identifying them so as to link them to one specific individual. Prior to this reading I did not know all the steps and procedures involved in a crime scene investigation. I like watching shows like CSI and NCIS and it was interesting to read about the stuff that you don't see going on in the show. They only show you the interesting stuff and leave out all the difficult and tedious tasks that must be done. It is hard, but very important to analyze a crime scene like this because the evidence you obtain has the power to change people's lives.

Terms: CSI Handbook, Dying Declaration, Forensic Science, Identification, Anthropometry, Biometrics, Trace Evidence, Qualitative Statement, Simple Match, Match Plus Statistics, Individuation, Loop, Whorl, Arch, Experimenter Bias, Double-blind Study, Credibility, Contamination

In chapter four the many forms of possible errors in forensic identifications are discussed. I was surprised by all the possible errors that can occur in the process of narrowing down suspects to find who the guilty individual is. The errors that can occur in fingerprint identification was the information that shocked me the most throughout the chapter. Primarily because I know that no two fingerprints are the same, but I never took into consideration that two can be very similar. I did not even think about the possibility of bias in identifying fingerprints. There was a study done in which untrained individuals were exposed to stimuli that would arouse ones emotions such as photos from a crime scene. In these situations those individuals were more likely to see the two prints as matching, this is a fantastic example of sensation and perception in law. Prior to reading chapter four I had no idea so many errors could occur in forensic science. In the CSI handbook the authors were giving a basic outline on how one should go about collecting and processing evidence and the rules that go along with it. I believe that the procedures for collecting evidence are reasonable. There needs to be strict guidelines that are followed so there is no cross contamination. There also needs to be a universal guide on how evidence is collected for the same reason.

Forensic science, CSI handbook, suspects, fingerprint, stimuli, crime scene, collecting, processing, sensation, perception, cross contamination, evidence

The CSI handbook it gives guidelines as to how you should treat a crime scence. Basically one of the key points what to analizye every crime scence like it's your first. I think that the procudres for collecting evidence are very reasonable because someones fate is in their hands, and if they get it wrong then they could make a false forensic identification. For an example, the bombs that exploded in Madrid's subway system.. Investagators had found a blue bag where they were able to lift fingerprints from and those prints were sent to the FBI crime lab in the United States. The fingerprint ended up matching Brandon Mayfield and a senior FBI fingerpring examiner declared that the prings were a 100% match. He was put into jail.
In chapter four it covers DNA, Fingerprings, and Physical Trace Evidence. Before fingerprints came into play Aplhonse Bertillon came up with a technique called anthropometry, which is taking measurements of the body.
When at the scene of a crime, police have a very important job. Trace evidence is left at a scence of a crime, if police find suspects then they can take a sample from them and compare it to the evidence left at the crime scene. If those two samples match then investagators have made a source attribution.
One thing that I had never heard about before reading this chapter was the "CSI Effect" I watch crime shows all of the time so this topic was really interesting. Personally I think that it would be really hard to get ALL of the evidence in a case, but if police are very percise, do their job how they are suppose to,and follow guidelines then they should not have a problem.
I really found the fingerprint section really interesting. It amazes me that each person can have a different set of fingerprints. I always used to think of fingerprints like license plates, and eventually I feel like they would have to "run out" of options.. but actually scientists do not really know wheter "no two fingerprints are identical: But science is really awesome and they are many options for finger prints such as the loop, whorl, arch, friction ridges, etc.

Terms: CSI Handbook, Forensic Identification, Anthropometry, Source Attribution,DNA, Friction Ridges, Loop, Whorl, Arch, Trace Evidence, CSI Effect

"Innocent until proven guilty." This is the encompassing philosophy of the legal system of our nation, the United States. A statement seemingly simple, yet it foretells nothing of what steps are actually required to be taken in order to prove a suspect guilty. This is where forensic evidence comes in. Chapter Four of the book talked a great deal about forensic evidence, and more so forensic science. Forensic science is the collection, analysis, and interpretation of physical evidence, and the identification of said evidence to an individual person. The chapter highlights many methods that have been used for identification in modern forensic science. From shoe prints to hair, bodily fluids to fingerprints, and a series of 11 measurements of the body to DNA, these are some of the methods prosecutors utilize for accurate identification. The chapter goes on, explaining how evidence is used for individual identification. Evidence that is left a crime scene is known as trace evidence. Using one of the methods for identification (today being primarily fingerprints and DNA), trace evidence is compared with samples from the suspect and/or from tools used at the crime scene. If the result is a match, it is said to come from a common source. There is a lot of room for error in making a positive match however. First, a sample is not always obtainable from a suspect. Also, contamination of the trace evidence can cause the evidence to become obscured, and thus not viable. The chapter continues discussion to the role of bias on criminal prosecution, a point that was the most surprising to me, and something that I had no idea about before. The tv shows we all know and love that illustrate a crime scene and how forensic science works, has placed a great deal of strain on the real world courts. In the shows, evidence seems to be readily obtainable, and matching results are quick and precise. This is obviously not the case in real life. However, these shows have created a bias, specifically for jurors, that raises the amount of evidence a jury will want to see to make a prosecution. The possibility of error in forensic evidence has lead the CSI to develop an extremely consice and caution focused system for the collection and analysis of evidence. The CSI handbook was exactly what common sense would dictate it to be: a handbook for a CSI responder. It outlined procedures in extraordinary detail, stating all steps necessary to limit contamination of evidence at the crime scene. The handbook goes so far as to have a list of gear a responder will require, as well as a list of things they may want to have with them while at a crime scene. It outlines step by step everything a responder must do from the time they arrive at the scene to the time the leave. Personally, I find the standards and procedures that are held for evidence collection to be very reasonable. Difficult, yes, but necessary to ensure viable evidence. Without such caution, evidence would be easily contaminated, and accurate prosecution would be near impossible. These rules are necessary to ensure that the right person is convicted for a given crime. While nothing is perfect, these steps reduce the likelihood of mistaken identification of a perpetrator because of contamination or bias by a substantial amount. There will always be imperfections in our legal system, and forensic science has not been around enough to be near perfect. But with the steps that are take to ensure its accuracy, I am certain that our forensics and legal system are doing the best job possible.
Terms: forensic evidence, forensic science, crime scene, trace evidence, identification, contamination, CSI Handbook

The first part of our assignment is covered by the CSI handbook. This is the law enforcement handguide on how to properly approach a crime scene. The first page stresses how important it is to ensure that the crime scene be preserved and the thoroughness needed. It's that detail that differentiates what everyone watches on t.v and what actually happens in real life. I have always enjoyed crime shows on T.V, but its interesting to me just how many people presume from watching those shows that how a crime scene is investigated in CSI, is what actually happens. To it'd be interesting to see Social Psychology to see how crime shows have affected the enviornment surronding jury decisions. I think all these rules surronding the crime scene while detailed and difficult are necessary. A case could hinge on one piece of evidence if not collected properly or not even found, could lead someone to getting away with a cime. Thats why I think the rules are in place, you can say its a better safe then sorry scenario. I'd rather it be overly complex than something that you can breeze through and miss important details. overall I think the CSI guidelines were an excellant addition to the chapter.

So chapter four was of course about Forensic Science. As defined Forensic Science is the collection, analysis, and interpretation of physical evidence. Next was identification which is the linking of evidence to the suspect/perpetrator of the crime. This is where the example at the beginning of the chapter. After the bombings in Madrid they found the evidence left in the van (the blue bags with finger prints) which may or may not have been left intentionally but prove th point there is no crime without some sort of evidence. Next the Spanish investigators sent the prints to the FBI for them to use their technology to find a match. After finding matches in their system and taking them to two redgeologists(finger print examiners). This led them to Brandon Mayfield, an attorney in Oregon; Who eventually was arrested after he was under covert surveilance amongst other things. It was found out he was a new convert to Islam and he was married to an Egyptian woman. With these facts he was arrested until his pre-trial. At this point in the show you'd normally have Mayfield being found guilty and the case is tied up with a bow. Except that isn't the case. The spanish investigators found out it wasn't Mayfield at all but a man named Ouhnane Daoud. Several days later the Mayfields case was dismissed. This shows the next point that no technology is perfect and that it still comes down to the humans behind this. In this case we deal with bias, could it have been Mayfields new found religion that led the FBI to going full tilt against him? Mayhaps. Its the implied bias that leads to stereotypical assumptions that jailed a man who was innocent! Overall I really enjoyed the chapter and thought it was interesting.
Terms: Forensic Science, Identification, CSI guidelines, bias, Social psychology, ridgeologists

I first read the "Crime scene investigation, A guide for Law enforcement". I thought that this guide was a very thourough guide filled with the steps that law enforcement office has to follow while at, and investigating a crime/crime scene. This includes the process of when officals arrive at a crime scene, and the protacall that they have to follow. For instance, officalls must not disturb the crime scene, for it they might misconstrue with the evidence. Crime scene investigators must be observant and to secure any people who are/could be involved in the crime. Which then leads to conducting an assessment of the crime scene, officers having to determine the types of investigation needed. Investigators then need to form a professional team to continue with the process. Once the team has continued with the investigative process a debriefing is conducted. This allows investigators to share their findings before allowing the public to be informed. Overall, I felt that this Investigation guide is a legitimate, important guide book for all legal law enforcement investigators to follow. I felt that I was familiar with how some of the investgative process worked because of watching CSI, and other forensic shows. But of course, those shows leave out how long of a process these investigations usually are. That part I didn't find surprising. I think that following these guidelines may be difficult to follow due to the fact that it is so specific, but I think it is a good thing to have. I think this because I feel that even the brightest investigators need to have something to fall back on, especially due to the variety of circumstances that the are involved in crime(s)/at the crime scene. Lastly, I read chapter 4. I found this chapter just as exciting as the investigation guideline book. This chapter explains how crucial it is for investigators to have the right evidence (i.e. DNA, hair samples, finger prints, ect.) in order to catch the right person. The story in the begining of the chapter about the Madrid subway explosion, shows how forensic identification can be over looked due to bias associated with one's culture/religion/race. The chapter proceeds in explaining the meanings in forensic identification, such as finding to samples that match/individuation and are identified as coming from a "common source". I never knew how specific finger printing could be. Of course as this text illustrates, there are still some weaknesses in how a computer scanning fingersprints can be misleading. Not only that, but the problem with identification bias which occures a lot with in law enforcement. Many people working within these fields have a different backgrounds, interests and experiences; the equation for forming bias. I think this is, and will be the largest "stab in the back" from law enforcement. Overall, I learned a lot about how the fingerprint scanning came into play, and how effective it can be. I was not surprised by how bias can occure with in the legal system; after a few psych/soc classes you learn that it is more common than what most people think.

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