Student Outline: Forensic Science Midterm Exam I. Introduction to Forensic Science

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1 Done For you: see class web page if you need a copy Student Outline: Forensic Science Midterm Exam I. Introduction to Forensic Science Define forensic science and describe it various disciplines. Describe the major events/people in the history of forensic science and relate them to modern-day practices. (See your notes and handouts, including power points for key event and people) Describe the 2 types of workers in public crime labs (enlisted and civilian) and the 2 major duties of a forensic scientists (analysis and testify in court, what do you have to demonstrate to be an expert witness) Describe the organization of federal, state, and local forensic science laboratories. Describe the organization of Forensic Science Laboratories and describe the flow of evidence from collection through a crime laboratory Describe the qualifications needed for becoming a forensic scientists. II. Crime Scene Investigations Describe role of the first officer at a crime scene List the steps in the investigation/ processing of a crime scene List the steps in the collection of evidence, what do you do if an object was moved or removed from scene Define chain of custody and describe its elements Packaging and preserving evidence List and describe the ways of searching a crime scene List and describe the ways of documenting a crime scene (include what elements a good crime-scene sketch has) Estimating time of death (rigor mortis, livor mortis, algor mortis, temperature, potassium in vitreous humor, settling of blood in body, entomology of death (what bug arrives first at a dead body), manners of death (see pg 59 in text) III. Nature of Evidence Define evidence, Describe the difference between the different types of evidence listed below and give examples: 1. physical vs. nonphysical 3. known vs. unknown 2. real vs. demonstrative evidence 4. individual vs. class Define identification and individualization, give examples Define and give examples of positive controls and negative controls Define false positive and false negative test and give examples What types of evidence are there maintained data bases for? IV. Fingerprints Define: friction ridges, anthropometry, layers of the skin, latent fingerprints, patent print, plastic print, iodine fuming, sublimes, silver nitrate, physical developer, ninhydrin, superglue fuming,. Describe the main events in the history of personal identification systems. Recognize the different types of fingerprint patterns and describe/draw the major types of ridge shapes: bifurcations, ending ridge, dot/island, short ridge, enclosure or anastomosis, trifurcaton. Describe what AFIS is and how it works (including the process for getting possible matches and for getting definitive matches.) What is forensic dentistry, dental impression vs. dental record analysis, procedure for analysis, how exact a science is this? V. Law Criminal vs. civil law Chain of custody Who is the final evaluator of forensic evidence? Witness, types and qualification Control s This is an optional assignment. Parts I III are done for you. Parts IV and V you will need to do on your own. Organize the material in any fashion you please and submit by the end of Q1 to earn extra credit.

2 Forensic Science Q1 Review Material I. Introduction to Forensic Science A. Define forensic science and describe it various disciplines. Criminalistics- the scientific study and evaluation of physical evidence in the commission of crimes. Pathology- the science or the study of the origin, nature, and course of diseases. Anthropology- the science that deals with the origins, physical and cultural development, biological characteristics, and social customs and beliefs of humankind. Odontology- the branch of science concerned with the anatomy, development, and diseases of teeth and related structures Engineering- the science dealing with the study of the teeth and their surrounding tissues and with the prevention and cure of their diseases. Entomology- the science dealing with the study of insects. B. Describe the major events in the history of forensic science and relate them to modern-day practices. (Please see notes and power points for full listing) a. Chinese- identification by fingerprints b. Romans bloody palm prints are evidence c. Marcello Malphighi- fingerprints exist and have interesting characteristics d. John Purkinji fingerprints can be classified e. Henry Faulds fingerprints can be used to identify people f. Juan Vucetich fingerprint classification systems still used today in South America g. Sir Edward Henry, Henry fingerprint system used in US and Europe h. First detective force, Surete of Paris, in 1810 i. Fist crime lab in France by Locard in 1910 j. FBI s first crime lab in 1932, L.A. k. Locard Exchange Principle l. First crime journals: Goddars in 1930: Scientific Crime Detection Laboratory at Northwestern University in Evanston, Illinois., changed to Journal of Police Science. m. Dr. Kirk, father of modern forensic science in US first college program in U.S.A. n. AAFS (American Academy of Forensic Science) based in Chicago, largest forensic science organization in world. C. Describe the 2 types of workers in public crime labs (enlisted and civilian) and the 2 major duties of a forensic scientists a. 2 types of workers in public crime labs i. enlisted and civilian b. 2 major duties of forensic scientists in crime labs i. analyze evidence ii. testify in court 1. lay vs. expert witness a. lay- eyewitness, victim, or other with knowledge of something that way help in determination of guilt. They are not to give opinion, only testify to what they perceive with their 5 scenes. i. Role of jury- to make scene of what was presented in court.

3 EX: If a whiteness offers testimony that the driver of a car involved in a traffic accident was drunk, that conclusion would not be permitted in court. Being drunk in the motor vehicle code sense requires an expert finding of sufficient alcohol in the driver s body exceeding the legal limit. b. Expert has knowledge and/or skills, derived from education and/or experience, that qualify him or her to take a set of facts and reach conclusions not attainable by the average person (judge or jury). Some or Ph.D. scientists or doctors, others may be experts from experience. c. It is the judge s responsibility to decide if expert testimony is needed and who is qualified to offer it. d. Even if a forensic scientists has testified hundreds of time, they may be required to equality at each trial. It is important that the expert explain the complex scientific or technical 0principles in a language that the jury can understand. EX: Brakes failed on car while driving down a mountain road, driver is killed. A man is now on trial for the death of this man. A whiteness is need to tell the court why the brakes failed. Who do you call? An expert brake mechanic. Terms: Trial by jury vs. Bench Trial (judge) c. Role of Forensic Scientists vs. role of Crime Scene Unit i. In general who will be at the crime scene, collect evidence vs. analyze evidence E. Describe the organization of Forensic Science Laboratories and describe the flow of evidence from collection through a crime laboratory F. Describe the qualifications needed for becoming a forensic scientists. a. Crime lab forensic science work: i. Entry-level lab technician: 1. BA in science such as biology, chemistry, or forensic science plus a year or two of experience or a master s degree with less experience. ii. Forensic pathologist: 1. 4-year degree, then medial school (another 4 years), then residency in pathology (another 4 years), additional residency in forensic pathology is recommended to become certified (1 year).

4 iii. Forensic anthropologist: 1. few labs can afford to hire one, even part time. So if you wish to work as one in a crime lab, specialize in another high demand area, such as DNA. The DNA analysts would get you hired and as anthropology cases come in you could work them. Option 2 is for you to get a Ph. D. and work in a college teaching or doing research. You could be hired to consult. iv. Forensic odontologist: 1. similar to a forensic pathologist in training. However, listed of medical school, you go to dental school. There are few, if any, residency opportunities for forensic Odontology. You would work with the police on an as needed basis. v. Forensic engineer: 1. engineering degree, usually a Ph. D. is needed. Most have their own private companies that are hired by prosecutors or defendants. See the American Academy of Forensic Science s web page for more info: II. Crime Scene Investigations A. Describe role of the first officer at a crime scene a. Is perpetrator still at the scene? i. Yes- hot search (run, chase, look) ii. no-cold search, later on (interview, look for witnesses, observations of suspicious events) b. Tend to injured, c. Secure the scene- Contamination must be minimized, limit people at scene, isolate d. Do not walk through the scene and search for evidence. Rather start to plan for a systematic search of the site later. e. Safety of the scene must be considered B. List the steps in the investigation of a crime scene.

5 List the steps in the collection of evidence How much do you collect as much as possible The lab should sort out what is brought in and make the decisions as to what they should and should not sample for analysis. If it can be shown that there was more evidence available then was collected the defense attorney may be able to have the evidence excluded from the trial on the grounds that the defense didn t have an opportunity to analyze the evidence with its own expert. Knows are needed. Collect them. Why? With many types of evidence its probative value, or significance, in the case can be greatly enhanced if it can be compared with and linked to a known object. Ex- lifted fingerprint are useless unless you have a known sample from the suspect to compare them to. C. Define chain of custody and describe its elements. Rules of evidence require: 1. that all evidence be authenticated (recorded of who is in possession of the evidence from the time it is collected at the crime scene until the time it gets to court). 2. Evidence must be uniquely identified in such a way so that it cannot be confused with any other piece of evidence and so that it can be shown that the evidence that is being used in court is the same evidence that was taken from the crime scene. 3. Evidence must be package in tamper-evident packaging

6 D. Packaging and Preserving Evidence

7 E. List and describe the ways of searching a crime scene. Zone: Line: line up and cover inch by inch Grid: large outside area. Spiral: small house. Crime in 1 room. Start at outer rooms and spiral way in. F. List and describe the ways of documenting a crime scene. Sketches with careful measurements and notations of locations of objects of interest in relation to a point or several points. Then scale sketches. Photography, still and video Reconstruct and reenact: ATF will rebuild a model of an important crime scene in an confined place are burn it and collect as much data as possible.

8 III. Nature of Evidence A. Define evidence Evidence- anything that would make as issue more or less likely than it would be without the evidence. B. Describe the difference between the different types of evidence listed below and give examples: 1. physical vs. nonphysical 2. real vs. demonstrative evidence 3. known vs. unknown 4. individual vs. class Physical objects or things. Nonphysical is verbal testimony about a crime, or it may be someone s actions during a crime. Ex -If someone is running away from a bank robbery holding a bog of money, the actions of running away is nonphysical evidence, the bag of money is physical evidence. Real- generated by criminal activity, often found at crime scene. Fingerprint, blood, drugs, bullets. Demonstrative- created to explain or clarify real evidence. Generated after crime by criminal investigator or forensic scientist. 3-d scale model of a crime scene made from photographs and measurements. OR A chart or graph from an analytical instrument that shows some property of a substance. Known evidence recovered from the crime scene, know where it came from. Usually use for comparison. Ex- break window, cut hand, climb into room, get glass in shoe. Glass in shoe and on floor is unknown till compared to know sample taken from the window. Unknown evidence at a crime scene whose source is unknown. Ex- bullet found in body of homicide victim. Individual evidence that could have arisen from only one source. Ex fingerprint lifted off coffee cup Class evidence that could have any of several possible sources. In most cases the number of possible sources is unknown. Ex blue jeans, so common never sure C. Define identification and individualization, give examples Identification-to put objects into successfully smaller groups.

9 Individualization-put into a class of one, example a one-to-one comparison of fibers or a fracture match with a known. Controls D. Define and give examples of positive controls and negative controls Negative control a known substance or material that would be expected to yield a negative result to a particular test. Should always be used when there is a question of a false positive. Ex- test a red stain on a shirt to see if it is blood. Test comes back positive. However, there are substances that will yield a false positive, so one runs the test again, this time on unstained fibers from the same shirt. It is expected that these fibers will test negative for blood. If they do, the original test is likely valid and correct. Positive control a known substance or material that would be expected to yield a positive result to a particular test. Ex human blood, test with same reagent used on shirt stain, it should come out positive. E. Define false positive and false negative test False positive a test comes out positive when it should be negative. False negative a test come out negative when it should be positive.

10 IV. Fingerprints A. Define: friction ridges- the visible raised pattern on the skin of hands and feet. Provides friction and hold on to objects. Anthropometry- first systematic method of personal identification. Relied on detailed description of person called portrait parle. A full length photograph and then careful measurment of body (anthropometry). Layers of the skin-fingerprints arise from the dermal papillae, the layer of cells between the epidermis (outer layer) and the dermis (inner layer). Sweat pores are in the dermal ridges. Latent fingerprints Sweat, skin cells, proteins, oils and other materials are deposited when you touch an object. You usually can not see them, so the are latent print. They must be visualized using various techniques. Patent print- a fingerprint that is deposited in paint or blood on a surface and is readily visible. plastic print a fingerprint formed in a soft material such as putty. iodine fuming oldest technique if visualizing. Iodine is a solid crystal at room temp, it sublimes (vaporizes) when heated and sticks to fingerprints making them red. silver nitrate makes prints visible as a white residue, was a liquid, could not use if water would damage, unstable in light. Older technique. physical developer a newer version of silver developing, it had a reducing agent added to it, could be used on any surface. Ninhydrin reacts to amino acids, good on porous surfaces like paper. Turns prints purple. superglue fuming Cyanoacrylate, the fumes of super glue will stick to prints making them white and very stable. Can use tank or wands. B. Describe the main events in the history of personal identification systems. 3,000 yrs ago - Chinese used finger prints on legal documents, no evidence that they could compare prints with a system 1870s William Herschel, British official posted in India, required any contract with indigenous people contain an imprint of their entire hand. However, no evidence that he had a system to link a hand print to a particular person Henry Fauld, paper on use of prints to id persons in journal Nature. While working in Japan as a missionary in a hospital discivered all prints look unique and can not be altered chemically. He saw value in crime investigations and helped Tokyo police solve bulgeries. Applied to Charles Darwin for funding, he passed it on to nephew Francis Galton who did not fund Fauld, but took credit for his work Alphonse Bertillion worked on france on a system of personal identification called Anthropometry (first systematic method of personal identification) Relied on detailed description of person called portrait parlé. A full length photograph and then careful measurment of body (anthropometry). Based on false idea that after age 18, human skeletal system stops growing and that no two people are identical. Used well into 1900s. in 1903 William West was sentenced to Levavenworth Prison in Kansas, he was getting process and they found that they already had him there and his card was on file. Puzzled, the investigated and fould they are different individuals who only differed physically in prints. Sir Francis Galton published book on finger print patters, loops, arches, and whorls. He asserted that all fingerprints were unique and that they didn t change throughout life. Shortly after 2 systems were developed: Juan Vucetich- Argentine police officer, developed the first classification system. Still used in South America, after a few refinements. Sir Edward Henry England, developed a different system, it has also been refined and is still used in Europe and the US. It used 5 classification to place prints into 1 of 1000 classes. This worked will until the FBI found they had too many samples in each class and searching became very difficult, to they added additional classes. C. Recognize the different types of fingerprint patterns

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14 D. Describe the major types of ridge shapes: Bifurcations: Ridges that split into two ridges Ending ridge: A simple straight ridge Dot/island: tiny round ridges Short ridge: A small, isolated segment of ridge Enclosure or Anastomosis: A ridge that forks and forms a complete circle, and then becomes a single ridge again. Trifurcaton: A ridge that splits into three ridges E. Describe what AFIS is and how it works. (Including the process for getting possible matches and for getting definitive matches. Automatic Fingerprint Identification System: developed by FBI, images of prints compiled into a searchable computer data-base. You scan in 10-print cards or sinlgle latent prints found at crime scenes, then have the system look for possible matches. It does this by searching bifurcations and ridge endings. Then all possible matches must be confirmed by hand, yielding a definitive match (definite, hand done, court case ready). V. Law 1. Criminal vs. Civil Law A. Who files suit: 1. In civil law, a private party (e.g., a corporation or individual person) files the lawsuit and becomes the plaintiff. 2. In criminal law, the litigation is always filed by the government, who is called the prosecution. B. Punishment. 1. criminal law: In criminal law, a guilty defendant is punished by either (1) incarceration in a jail or prison, (2) fine paid to the government, or, in exceptional cases, (3) execution of the defendant: the death penalty. Crimes are divided into two broad classes: felonies have a maximum possible sentence of more than one year incarceration, misdemeanors have a maximum possible sentence of less than one year incarceration. 2. civil law: In contrast, a defendant in civil litigation is never incarcerated and never executed. In general, a losing defendant in civil litigation only reimburses the plaintiff for losses caused by the defendant's behavior. 2. Chain of Custody The chain of custody of evidence is a record of individuals who have had physical possession of the evidence. Documentation is critical to maintaining the integrity of the chain of custody. Maintaining the chain of custody is vital for any type of evidence to be considered admissable to the legal process. All those who handle evidence at any time must obey the chain of custody rule. If they is a breach in procedure at any time the evidence may not be used in a legal case. 3. Who is the final evaluator of forensic evidence? Though law enforcement agencies expend a great deal of time and money collecting and analyzing evidence it is the jury or judge (depending on the trial type) who is the ultimate evaluator of evidence. That individual (or individuals) are charged with deciding if the evidence was collected in a lawful fashion, handled and evaluated correctly and what it mean. If the prosecution does not

15 convince the jury or judge that the evidence is valid and supports the guild of the defendant then they jury cannot convict. 4. Witness, types and qualification (taken directly from: on 01/17/12) G. Eye-witnesses You may be called as an "eye-witness" if you personally witnessed something happen that is relevant to the case. You may be called by either side in the case, whether it is a criminal case or a civil case. When you take the stand, a Bible will be handed to you and you will repeat the oath or affirmation that you will "tell the truth, the whole truth and nothing but the truth". You will then be asked a series of questions to allow you to describe what you witnessed. Your evidence as an "eye-witness" will be confined to the facts, i.e. what you actually saw, rather than any inferences or assumptions you have made from what you saw. You will then be cross-examined by the other side. H. Expert witnesses You may be called as an "expert witness" by either side in a case about a matter that is outside the ordinary knowledge of the judge or jury. For example, you may be called as a handwriting expert or as a doctor to give an opinion on something that is relevant to the case. Your opinion is accepted as evidence because you are an expert on the subject and because the court does not have the knowledge or expertise itself to form a reliable opinion on the facts. As an expert witness, you must also take the oath or affirmation. You will then be asked to explain why you are an expert in the particular area, i.e. to outline your qualifications or work experience. You will then be asked a series of questions to allow you to give your opinion about certain facts. Finally, you will be cross-examined by the other side. I. Character witnesses There are different situations where you may be called as a "character witness": You may be called as a character witness to give evidence of the good character of the accused in a criminal case. You will take the oath or affirmation and you will then be asked a series of questions to allow you to describe the accused. The purpose of your evidence is to show that the accused is less likely to have committed the offence because he or she is a person of good character. You may be called as a character witness to give evidence of the good character of a person who has already been convicted of a criminal offence. The purpose of your evidence is to help the judge decide which sentence to impose. You may be called as a character witness to give evidence about the good or bad character of a party in a civil trial if that party's character is an important issue in the case. For example, in a defamation case where a newspaper stated that a person was a "rogue", you may be called to give evidence about an incident you witnessed that tends to show that the person in question was of dubious character. You will make the oath or affirmation and then you will be asked a series of questions to allow you describe what you know of the party's character. You will then be cross-examined by the other side.