Exam I

Chapters 1-3, Supplementary Information, Labs 1-4

Chapter 1 Introduction1. What is forensic science?

• Forensic science is the study and application of science to matters of law (criminal and civil).

2. What is the difference between a criminalist and a criminologist?

• A criminalist examines physical evidence for legal purposes.

• Criminologists study the crime scene for motive, traits, and behavior as to help interpret the evidence.

3. What do forensic scientists do?

• Apply the principles and techniques of the physical and natural sciences to the analysis of the many types of evidence that may be recovered during a criminal investigation

• May also provide expert court testimony• Forensic scientists also participate in training

law enforcement personnel in the proper recognition, collection, and preservation of physical evidence.

4. Who was Edmond Locard? What is Locard’s exchange principle?

• Edmond Locard- considered the father of criminalistics; established first crime lab in Lyons, France in 1910

• Locard’s exchange principle- states that when a criminal comes in contact with an object or a person, a cross transfer of evidence occurs

5. What factors have contributed to the growth in crime labs?

• Supreme Court decisions in the 1960s placing greater emphasis on scientifically evaluated evidence

• Accelerated drug abuse• Initiation of DNA profiling

6. Know the primary functions of the five crime units:

• Physical Science- incorporates the principles of chemistry, physics, and geology to identify and compare physical evidence

• Biology- applies the knowledge of biological sciences in order to investigate blood samples, body fluids, hair, and fiber samples

• Firearms- investigates discharged bullets, cartridge cases, shotgun shells, and ammunition

• Document- provides the skills needed for handwriting analysis and other questioned document issues

• Photographic- applies specialized photographic techniques for recording and examining physical evidence

7. What are the functions of the toxicology and forensic pathology units?

• Toxicology- examines body fluids and organs for the presence of drugs and poisons

• Forensic Pathology- concentrates closely on the understanding of types and causation of injuries and causes of sudden and unnatural death

8. What are rigor mortis, livor mortis and algor mortis?

• Rigor mortis results in the shortening of muscle tissue and the stiffening of body parts in the position at death (occurs within the first 24 hours and disappears within 36 hours).

• Livor mortis results in the settling of blood in areas of the body closest to the ground (begins immediately on death and continues up to 12 hours).

• Algor mortis results in the loss of heat by a body (a general rule, beginning about an hour after death, the body loses heat by 1 to 1.5° Fahrenheit per hour until the body reaches the environmental temperature).

9. Know what other forensic services do including:

• Forensic Anthropology- concentrates on the identification of deceased individuals whose remains are decomposed, burned, mutilated or otherwise unrecognizable

• Forensic Entomology- is the study of insects and their relation to a criminal investigation, commonly used to establish the time of death

• Forensic Psychiatry- work with courts in evaluating an individual's

competency to stand trial, defenses based on mental diseases or defects (e.g., the "insanity" defense), and sentencing recommendations

• Forensic Odontology- evaluates teeth to determine the identification of the deceased

• Forensic Engineering- investigation of materials, products, structures or components that fail or do not operate/function as intended, causing personal injury for example

• Cybertechnology- involves the examination of digital evidence

10. What is an expert witness?

• An expert witness is an individual whom the court determines possesses knowledge relevant to the trial that is not expected of the average person.

• The expert witness is called on to evaluate evidence based on specialized training and experience that the court lacks the expertise to do.

• The expert will then express an opinion as to the significance of the findings.

11. What is the Frye Standard?

• The Frye v. United States decision set guidelines for determining the admissibility of scientific evidence into the courtroom.

• To meet the Frye standard, the evidence in question must be “generally accepted” by the scientific community.

12. How did Daubert v. Merrell Dow Pharmaceutical, Inc. modify

the Frye Standard? • In the 1993 case of Daubert v. Merrell Dow

Pharmaceutical, Inc., the U.S. Supreme Court asserted that the Frye standard is not an absolute prerequisite to the admissibility of scientific evidence.

• Trial judges were said to be ultimately responsible as “gatekeepers” for the admissibility and validity of scientific evidence presented in their courts, as well as all expert testimony.

What are the Daubert Criteria? • In Daubert, the Supreme Court offered some guidelines as to

how a judge can gauge scientific evidence: 1. Whether the scientific technique or theory can be (and has

been) tested. 2. Whether the technique or theory has been subject to peer

review and publication. 3. The technique’s potential rate of error. 4. Existence and maintenance of standards controlling the

technique’s operation. 5. Whether the scientific theory or method has attracted

widespread acceptance within a relevant scientific community.

Lab 1 Practice in making laboratory measurements (Appendix, Experiment 1)

13. Be able to convert within and to the metric system.kilo- (k) 1,000hecto- (h) 100deka- (dk) 10meter/liter/gram 1deci- (d) 0.1centi- (c) 0.01milli- (m) 0.001

units you x conversion factors = units youhave want

• You will be given any necessary conversion factors.

14. Be able to calculate the density of rectangular, cylindrical and irregular objects.

• Density = Mass Volume

• Volumerectangular- length x width x heightcylindrical- πr2hirregular- displacement of water

Chapter 2 The Crime Scene15. What is physical evidence?

• Physical evidence encompasses any and all objects that can establish that a crime has been committed or can provide a link between a crime and its victim or a crime and its perpetrator.

16. Why does forensic science begin at the crime scene?

• Forensic science begins at the crime scene because if the investigator cannot recognize physical evidence or cannot properly preserve it for laboratory examination, no amount of sophisticated laboratory instrumentation or technical expertise can salvage the situation.

17. What is Locard’s principle?

• States that:- Criminals always take a trace of something from the crime scene with themor - They leave a trace of something behind at the scene of the crime.

18. What are the first steps taken at a crime scene?

• First priority should be given to obtaining medical assistance for individuals in need of it and to arresting the perpetrator.

• As soon as it is possible, extensive efforts must be made to exclude all unauthorized personnel from the scene.

19. What steps need to be taken in order to properly secure a crime scene?

1) Identify and contact the office in charge (OIC) of the scene.2) Identify all other persons who have or have had access to the scene.3) Establish the scope and range of the scene.4) Physically secure the scene with police line tape or by other means and have law enforcement officers available to enforce the scene perimeter.5) Secure the scene.6) Interview initial responding officers (RO’s).7) Establish the perpetrator’s path of entry and exit.8) Do an initial walk-through.9) Develop a strategy for systematically examining/investigating and documenting the scene.

20. How are crime scenes recorded?

1) Photography- Crime scene photography is very important especially for establishing the physical relationships of items of interest (furniture, stains, weapons, bodies, etc.).

2) Sketches- A sketch of the overall crime scene noting the relative location of items along with detailed sketches and comments about various items of evidence is extremely important.

3) Detailed notes- These are critical since often you will be asked about the scene in court long after the investigation has taken place. Contemporaneous notes are the only way you will ever be able to accurately and truthfully be able to describe and recall events and observations.

21. What types of pictures need to be taken at a crime scene?

a) Establish overall shots of the scene– this includes: 1) the entire scene2) surrounding areas3) points of exit and entry

b) Area shots showing the general relationship of itemsc) Medium range shots showing the aspect and positioning of itemsd) Close-ups showing details of interest on the evidence items

22. What needs to be recorded on a rough sketch? How does a rough sketch differ from a finished sketch?

• Rough sketch- made at the time of the investigation and needs to include: 1) an overall view including the relationship of items to each other2) all recovered items of physical evidence3) all other important items of the crime scene4) location of objects by use of measurements5) identification of all items by use of identifying numbers or letters which match with the investigator’s evidence property log

• Finished Sketch – this is made after the fact from the rough sketch and should be neat, well-drawn with all items easily identifiable. All measurements should be as accurate as possible and should locate the item from at least two (2) landmarks (walls, doorways, fences, etc.)

23. What types of notes need to be made at a crime scene?

• Scene– a detailed written description of the scene with the location of the items of physical evidence recovered. They should include:

1) time of discovery2) who discovered it3) how it was discovered4) who handled the item before packaging5) who packaged and marked the item6) disposition of the item

• Details– this may be the only record of the scene that exists after a period of time. The note taker should put down as many details as possible at the time the notes are taken. Only contemporaneous notes are allowed as evidence in court.

24. Know the difference between types of search patterns:

25. What is trace evidence?

• Trace evidence- very small items associated with cross-transfer; usually have to be evaluated back at the laboratory

26. What is proper packaging for biological evidence?

• Biological evidence should NOT be packaged in airtight containers due to the moisture content as it will start to mold very quickly and this mold will damage the evidence. Paper envelopes and/or paper bags should be used.

27. What information should be included on a proper evidence label?

• Proper labeling includes the following:a) the investigating agency’s case numberb) the scene site (especially if more than one scene is

involved)c) a brief description of the evidence or the evidence item number which correlates to an evidence logd) the location where the evidence was obtained within the scenee) the collector’s name or badge no. and initialsf) the date and time collected

28. What is chain of custody and why must it be maintained?

• chain of custody- a log indicating the transfer of custody to and from every individual who is involved in transporting or storing the evidence from crime scene to and from crime lab

• It must be maintained to account for anyone who has handled the evidence and ensure no one else handles the evidence.

29. What allowances have been made for warrantless searches?

• A number of allowances have been made for warrantless searches (which would normally violate the 4th Amendment):

1) the existence of emergency circumstances2) the need to prevent the immediate loss ordestruction of evidence3) a search of a person and property within the immediate control of the person provided it is made incident to a lawful arrest (probable cause)4) a search made by consent of the parties involved

30. Know the Mincey v. Arizona and Michigan v. Tyler cases.

• Mincey v. Arizona– The court decided that a 4-day search following a warrantless entry in response to an officer-involved shooting was not legal and the evidence obtained which was used to convict Mincey was thrown out and the conviction was overturned.

• Michigan v. Tyler – Following the burning of a building, three additional searches of the premises turned up evidence of owner-initiated arson. The court ruled that the three subsequent trips into the premises without a warrant being obtained were illegal searches and the conviction was overturned. The search of the buildings following the initial response to the fire was allowed though warrantless since it immediately followed the initial entry by firefighters.

31. What items should be collected and sent from the medical examiner to the forensic laboratory?

• The following are to be collected and sent to the forensic laboratory:1. victim’s clothing2. fingernail scrapings3. head and pubic hairs4. blood (for DNA and typing purposes)5. vaginal, anal, and oral swabs (in sex related crimes)6. recovered bullets from the body7. hand swabs from shooting victims (for gunshot residue

analysis)

Lab 2 Locard’s Principle: Recording and collection of evidence

32. What is Locard’s exchange principle?• Locard’s exchange principle states that a

transfer occurs whenever a person comes in contact with another person or an object. This principle allows forensic scientists to connect a victim and crime scene to one or more suspects in a case.

33. How did Locard’s exchange principle influence your collection and handling of the evidence?

• It also mandates that forensic scientists must take care to minimize transferring materials from themselves to the evidence by using gloves and disposable/cleaned collection materials.

34. Why is it important to maintain the chain of custody for evidence?

• To account for any handling, and possible contamination, of evidence

• To minimize chances of tampering

Chapter 3 Physical Evidence35. What is the purpose of identification of physical evidence and

how is it accomplished?

• Identification: The process of determining a substance’s physical or chemical identity. Drug analysis, species determination, and explosive residue analysis are typical examples of this undertaking in a forensic setting.

• Identification has as its purpose the determination of the physical or chemical identity of a substance as near absolute certainty as existing analytical techniques will permit.

• To do this requires the analysis and ultimate identification of a specific physical or chemical substance to the exclusion of all other possible substances.

36. What are reference standards/samples?

• reference standards/ samples- known samples on which tests are established and to which unknown samples may be compared

37. What is the purpose of comparison of physical evidence and how is it accomplished?

• Comparison: The process of ascertaining whether two or more objects have a common origin.

• A comparison analysis subjects a suspect specimen and a standard/reference specimen to the same tests and examinations for the ultimate purpose of determining whether they have a common origin.

• e.g. hair found at a scene to hair from a suspect, a paint chip found at a scene with the paint from a suspect vehicle, fibers found on a victim with fibers found in suspect’s back seat

38. What are individual characteristics? What are class characteristics?

• Individual Characteristics: Properties of evidence that can be attributed to a common source with an extremely high degree of certainty.

• e.g. ridge characteristics of fingerprints, random striation markings on bullets or tool marks, irregular and random wear patterns in tire and footwear impressions

• Class Characteristics: Properties of evidence that can be associated only with a group and never with a single source.

• e.g. paint chips, blood type

39. Be able to apply the product rule.

• Product Rule: To obtain the probability of properties occurring together, multiply the individual probability of each property occurring on its own.

• e.g. Case 1Blond hair (32%), Type O blood (43%), Arch fingerprints (5%)0.32 x 0.43 x 0.05 = 0.00688 = 0.688%

40. What is the challenge of using probability values?

• One of the current weaknesses of forensic science is the inability of the examiner to assign exact or even approximate probability values to the comparison of most class physical evidence.

41. Know the types of information stored in the following databases: IAFIS, CODIS and IBIS.

• Integrated Automated Fingerprint Identification System (IAFIS)

• Combined DNA Index System (CODIS)• Integrated Ballistic Identification System (IBIS)

42. How can physical evidence be used to solve crimes?

• paint• glass• explosives• ballistics• dust and dirt• fingerprints• shoeprints• tire tracks• bite marks

• tool marks• fracture matches• wounds• questioned documents• insects• DNA• body fluids• hairs and fibers

43. What is forensic pathology?

• Forensic pathology- involves the investigation of sudden, unnatural, unexplained, or violent deaths.

44. What are rigor mortis, livor mortis and algor mortis?

• Rigor mortis results in the shortening of muscle tissue and the stiffening of body parts in the position at death (occurs within the first 24 hours and disappears within 36 hours).

• Livor mortis results in the settling of blood in areas of the body closest to the ground (begins immediately on death and continues up to 12 hours).

• Algor mortis results in the loss of heat by a body (a general rule, beginning about an hour after death, the body loses heat by 1 to 1.5 degrees Fahrenheit per hour until the body reaches the environmental temperature).

45. What information can be determined from skeletal remains?

• Forensic anthropologists analyze skeletal remains to determine four characteristics of a victim:

Sex- determined by examining the pelvis, humerus, and femur Age and stature- determined by analyzing the development of the

teeth, bone growth, and the length of specific bones, such as the femur.

Race- determined by analyzing the skull for characteristics that are common among people of different races.

• DNA samples can be collected from bone, teeth, and hair to provide clues to a person’s identity.

• Scientists may also be able to gain clues as to a person’s past, recent injuries, or the cause of death based on bone fractures and other signs of trauma.

46. What do forensic anthropologists do?

What a forensic anthropologist does DO to aid in a case:• Goes to a crime scene to assist in the collection of human remains • Cleans up the bones so that they may be examined • Analyzes skeletal remains to establish the profile of the individual • Looks at trauma evident on the bones to establish the pathway of

a bullet or the number of stab wounds • Works with a forensic odontologist (dentist) to match dental

records • Testifies in court about the identity of the individual and/or the

injuries that might be evident in the skeleton

Lab 3 Cause of Death Autopsy I47. When is an autopsy conducted?

• It depends on the jurisdiction, but autopsies may be requested or required under the following circumstances:

1) If the person died suddenly, with no obvious disease and no recent medical attention. 2) If there were suspicious circumstances, especially involving drugs, alcohol, or other toxic substances. 3) If the death was violent or traumatic, and may have been homicide, suicide, or an accident. 4) If the person died on the job. 5) If the death occurred as part of diagnosis or treatment for a disease. 6) If the body was unidentified or unclaimed.

48. Be able to appropriately use the following directional terms:

• caudal- toward the tail• cranial- toward the head • dorsal- toward the back• ventral- toward the belly• superior- above• inferior- below• anterior- in front of• posterior- behind • medial- toward the midline• lateral- away from the midline• proximal- closer to the trunk• distal- farther from the trunk

49. Know the terms cyanosis, jaundice, ascites and edema.

• cyanosis- bluish color, a sign of inadequate oxygen

• jaundice- yellow color, a sign of bile remaining in the body, often associated with problems of the liver

• ascites- accumulation of fluid in the abdomen • edema- accumulation of fluid in tissues, often

in segments of the body like the arms and legs

50. What are rigor mortis, livor mortis and algor mortis?

• Rigor Mortis: With humans, rigor mortis describes the change in which muscles stiffen (lack of ATP) then relax (deterioration of muscle fibers).

• Livor Mortis: Blood is kept moving by the heart; when the heart stops, the blood is no longer pumped. Initially, there will be no accumulation of blood, so livor mortis is absent. However, blood cells will follow gravity and begin settling in the lowest accessible areas. This pooling of blood cells is called livor mortis and can be pink or purple. If the body is shifted, the cells will shift also, and livor mortis is non-fixed. As time passes, though, the blood vessels weaken, and blood cells move out of the vessels and into tissues. Once in the tissues, the cells no longer have easy-to-follow pathways and tend to stay in the tissues, and livor mortis is fixed.

• Algor Mortis: With humans, a live body maintains an internal temperature of 98.6° F (37° C). Following death, the body will gain or lose temperature based primarily on the environment. The temperature will usually begin to drop for a day or two, although it may then increase as bacteria begin multiplying. Eventually, the body equilibrates-- it matches the temperature of the environment.

51. Know the terms contusion, abrasion, laceration, puncture and incision.

• contusion- a bruise; a superficial injury, due to impact, without breaking the skin

• abrasion- a scrape, a mechanical wearing away of skin• laceration- a rip; a wound with torn, ragged, or mangled

edges; skin was broken but not because of sharp edge • puncture- a hole; a pierced, penetrated, or punctured wound;

skin was broken, with narrow but possibly deep wound, made by narrow but long object (e.g., nail, needle, syringe)

• incision- a cut, a wide but relatively shallow wound made by a sharp object (use this if cutting object is unknown-- see also knife wound)

52. What is an autopsy?

• An autopsy is a post mortem examination preformed on a corpse to determine the cause and manner of death.

• The prefix auto- means “self” and so autopsy means “to see for oneself.”

53. Know when to use one of the five categories of death:

• Natural- used to describe the death of someone by occurring disease process, or that is not apparent given medical history or circumstances

• Accidental- a death that is often caused by mistake or in a freak occurrence

• Homicidal- the act of killing another person• Suicidal- the act of ending one’s own life • Unknown- may include deaths in absentia, such as

deaths at sea and missing persons declared dead in a court of law

54. What warrants an autopsy?

• Questionable death- as determined by the coroner

• Homicide• Drowning• Auto accidents• Death of a child

55. What is involved in an external examination?

• The external examination consists of inspecting the physical outer layer of the body for signs of foul play that would result in injury or death.

• Steps of an external examination:1. Photographed. 2. Physical evidence collected off body.3. Samples of hair, nails, etc. are collected.4. Undressed, examined for wounds (lacerations,

abrasions, bruises).5. Measured, weighed, cleaned.

56. What are rigor mortis, livor mortis, algor mortis and pallor mortis?

• Rigor Mortis- “Stiffness of Death,” flexibility of the body; begins with eyelids, then jaw, face, trunk, arms and legs

• Livor Mortis- “Color of Death,” color of the body; blood cells and plasma gather on the lowest part of the body; line forms after 8 hours

• Algor Mortis- “Coolness of Death,” temperature of the body

• Pallor Mortis- “Paleness of Death,” tone of the body

57. What is involved in an internal examination?

• The internal examination consists of inspecting the internal organs of the body for evidence of trauma or other indications of the cause of death.

• Steps of an internal examination:1. Incisions2. Cut- the chest cavity is cut open using shears and the ribs are sawed away.3. Removal4. Each organ is:- weighed and measured- examined- sliced in cross-sections- sampled for microscopic and chemical analysis5. Exposing the skull and exposing and removing the brain6. Close up

58. Know the different autopsy methods:

• Letulle Method- all organs removed at once, “en masse”

• Ghon Method- organs divided into groups and removed “en bloc”

• Virchow Method- one organ at a time • Rokitansky Method- organs dissected in situ

59. What is the difference between qualitative and quantitative analysis?

• Qualitative analysis- determines the presence or absence of a drug or poison in a submitted sample

• Quantitative analysis- determines the amount of drug or poison that is present in the submitted sample

60. What types of samples can be collected for postmortem forensic toxicology?

• Blood• Urine• Stomach contents• Bile• Liver• Vitreous humor• Hair

61. What is a hematoma and what can it reveal about a deceased individual?

• hematoma- extravascular blood clot; protected from metabolism

• Analysis will indicate what drugs were present in the blood at the time of formation of the hematoma.

62. Where in the body are drugs metabolized?

• liver

63. What is vitreous humor and how is it useful to forensic toxicologists?

• vitreous humor- fluid that occupies the space between the lens and the retina of the eye.

• Sequestered from putrefaction, charring, trauma, and microorganisms.

• Useful in cases where decomposition is advanced, body is exhumed or in fire deaths.

64. How should specimens be properly stored and handled?

• Identification of samples• Placed in sterile, well-sealed containers• Specimens delivered to lab without delay• Specimens should be analyzed as soon as

possible• Storage areas should be secure

65. What are some pitfalls in postmortem forensic toxicology?

• Decomposition- autolysis, putrefaction; fewer samples available for collection and quality of samples is diminished

• Postmortem redistribution- a phenomenon whereby increased concentrations of some drugs are observed in postmortem samples and/or site dependent differences in drug concentrations may be observed.

• Drug stability• Evaporation• Interpretation

Lab 4 Cause of Death Autopsy II

66. Be able to identify the locations of organs in the fetal pig: heart, lungs (thoracic cavity), liver, gallbladder, kidneys, bladder, spleen, pancreas,

stomach, small intestine, large intestine (abdominal cavity).