1. Unit 1: Introduction to Forensic Science and Evidence

2. What is forensic science?

3. Forensic Science Definition:
The study and application of science to matters of law.

4. Jobs of Forensic Scientists:
Analyze & examine Evidence
Follow scientific protocols
Provide timely, accurate, and thorough information
Testify in court regarding results of analysis

5. Types of Forensic Scientists:
Anthropologist
Odontologist
Entomologist
Pathologist
Toxicologist
Serologist
Crime Scene Technician

6. Crime Lab Units Physical Science Unit
Glass/Fibers/Soil/Impressions/ Markings
Biology Unit
Serology (blood)
DNA Analysis & Blood Splatter
Anthropology (Human Remains)
Pathology (disease)
Odontology (teeth)
Firearms Unit
Ballistics
Document Examination Unit
Forgery
Toxicology
Drugs
Latent Fingerprint
Polygraph
Voiceprint Analysis
Cybertechnology
Psychiatry
Accounting
Arson
Evidence Collection
Crime Scene Investigators

7. Major Crime Laboratories
FBI-Federal Bureau of Investigation
Full Service
DEA-Drug Enforcement Administration
Drug Investigations
ATF-Alcohol Tobacco and Firearms
Firearms/Bombs
U.S. Postal Service
Crimes involving mail
U.S. Fish and Wildlife Service
Environmental Services

8. What is evidence? What do you think the definition of evidence is?
What types of evidence can you think of?

9. What is evidence? Definition:
anything that tends to establish or disprove a fact

10. Federal Rules of Evidence
In order for evidence to be admissible, it must be:
Probative—actually prove something
The more directly linked to a suspect the more probative it is
Example: Fingerprints are more probative than fibers or glass found at the scene
Material—address an issue that is relevant to the particular crime

11. Admissibility of Evidence
1923 Frye v. United States
Scientific evidence is allowed into the courtroom if it is generally accepted by the relevant scientific community.
The Frye standard does not offer any guidance on reliability. The evidence is presented in the trial and the jury decides if it can be used.

12. Categories of Evidence
Direct Evidence
Proves a direct fact
Examples:
Eyewitness Testimony
Surveillance Video
Circumstantial Evidence (aka Indirect Evidence)
Implies a fact (but does not prove it directly)
Most types of evidence fall under this category
Physical and Biological Evidence
Hair/Blood/Fingerprints/Documents/Glass/Impressions etc.

13. Classification of Evidence by Nature
Biological—blood, semen, saliva, sweat, tears, hair, bone, tissues, urine, feces, animal material, insects, bacterial, fungal, botanical
Chemical—fibers, glass, soil, gunpowder, metal, mineral, narcotics, drugs, paper, ink, cosmetics, paint, plastic, lubricants, fertilizer
Physical—fingerprints, footprints, shoe prints, handwriting, firearms, tire marks, tool marks, typewriting
Miscellaneous—laundry marks, voice analysis, polygraph, photography, stress evaluation, psycholinguistic analysis, vehicle identification

14. Evidence Characteristics
Class—common to a group of objects or persons
Individual—can be identified with a particular person or a single source
Fibers
Shoe Prints
Fingerprints
Shoe Prints
Blood DNA Typing

15. Class or Individual?
These fibers are class evidence; there is no way to determine if they came from this garment.
The large piece of glass fits exactly to the bottle; it is individual evidence.

16. Eyewitness Testimony (Testimonial Evidence)
Statement under oath by a competent witness

17. Expert Testimony
Testimony made by a qualified person about a scientific, technical, or professional issue.
Effectiveness Depends On:
Their experience level
Their education
How well they communicate
Cannot be hearsay
Secondhand information
I heard that he…

18. How to be a Good Observer
Observe systematically—
Start at one part of a crime scene and run your eyes slowly over every space.
Slowly look at every part of a piece of evidence.
Do not assume that later on you will be able to remember everything.

19. How to be a Good Observer
Turn off filters—
Do not pay attention to only what you think is important.
On a crime scene you will not know what will turn out to be important.
Make a conscious effort to pay attention to all the details in your surroundings.

20. How to be a Good Observer
Interpret Data Later—
Do look for patterns and make connections.
But the more information obtained, the better will be the interpretations.
Remember that eyewitness accounts and your own thinking can include prejudices.

21. How to be a Good Observer
Documentation—
It is important to write down and photograph as much information as possible.
Keep in mind that memory is faulty.
Remember that our brains tend to automatically fill in gaps in our perceptions.

22. Are You a Good Eyewitness??
You will have 30 seconds to look at a picture and study it.
When time up, I will ask you several questions about the picture.
Answer the questions on the handout
When we are done we will find out who would make a good eyewitness!!!

23. READY?

24. PICTURE 1

25. Questions At what location was the photograph taken?
How many cars are pictured?
What color are the cars?
 What types of offices are located in the building?
 How many small trees are in the picture?
The photograph was taken in New York State during which season?
How many people are in the photograph?

26. READY?

27. PICTURE 2

28. Questions What is pictured in Photograph 2?
Describe the shape of the object pictured.
What are the colors of the object?
What color edged the top of the object?
Upon what is the object displayed?
Describe or sketch the design on the object.
What is the approximate size of the object?

29. READY?

30. PICTURE 3

31. Questions How many people are in Photograph 3?
What is the sex of the person in the picture?
What is the approximate age of the person in the photograph?
What color is the person’s hair?
Does the person have long hair or short hair?
Does the person have any distinguishing features? Glasses?
Can you describe the person’s clothing?
Can you describe where the picture was taken?
Based on evidence in the photograph, can you form a hypothesis about the person’s occupation?
Is it possible to identify the interests of the person based on evidence in the room?

32. Discussion Questions
1. Did everyone answer all of the questions correctly? 2. Did everyone have the same answers? If not, why? 3. Did you do better with practice? 4. Do you think your observations changed when you were distracted? 5. Would your answers have been good enough to testify in court?

33. Problems with Testimonial Evidence

34. Observations by Witnesses
Affected By:
Emotional states (stress level)
More stress = Less detail
Prejudice
Ulterior Motives
Interrogation/Questioning Tactics Used
Time

35. The Innocence Project
Barry C. Scheck and Peter J. Neufeld at the Benjamin N. Cardozo School of Law, starting in 1992, use DNA to examine post-conviction cases.
The project has found that up to 87% of the wrongful convictions they discovered were due to faulty eyewitness identifications.

38. Original Composite Sketch of Cotton

39. The Case of Ronald Cotton Part 1

40. The Case of Ronald Cotton Part 2

42. Value of Physical Evidence
Generally more reliable than testimonial
Can prove that a crime has been committed
Can corroborate or refute testimony
Can link a suspect with a victim or with a crime scene
Can establish the identity of persons associated with a crime
Can allow reconstruction of events of a crime

43. Reconstruction
Physical Evidence is used to answer questions about:
what took place
how the victim was killed
number of people involved
sequence of events
A forensic scientist will compare the questioned or unknown sample with a sample of known origin (control sample).

44. Types of Physical Evidence
Transient Evidence—temporary; easily changed or lost; usually observed by the first officer at the scene
Pattern Evidence—produced by direct contact between a person and an object or between two objects
Conditional Evidence—produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances or sequence within a particular event
Transfer Evidence—produced by contact between person(s) or object(s), or between person(s) and person(s)
Associative Evidence—items that may associate a victim or suspect with a scene or each other; ie, personal belongings

45. Examples of Transient Evidence
Transient Evidence—temporary; easily changed or lost; usually observed by the first officer at the scene
Odor—putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke
Temperature—surroundings, car hood, coffee, water in a bathtub, cadaver
Imprints and indentations—footprints, teeth marks in perishable foods, tire marks on certain surfaces
Markings

46. Examples of Pattern Evidence
Pattern Evidence—most are in the form of imprints, indentations, striations, markings, fractures or deposits.
Clothing or article distribution
Gun powder residue
Material damage
Body position
Tool marks
Modus operandi (how they did it)
Blood spatter
Glass fracture
Fire burn pattern
Furniture position
Projectile trajectory
Tire marks or skid marks

47. Examples of Conditional Evidence
Conditional Evidence—produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances or sequence within a particular event
Light—headlight, lighting conditions
Smoke—color, direction of travel, density, odor
Fire—color and direction of the flames, speed of spread, temperature and condition of fire
Location—of injuries or wounds, of bloodstains, of the victim’s vehicle, of weapons or cartridge cases, of broken glass
Vehicles—doors locked or unlocked, windows opened or closed, radio off or on (station), odometer mileage
Body—position, types of wounds; rigor mortis
Scene—condition of furniture, doors and windows, any disturbance or signs of a struggle

48. Examples of Transfer Evidence
Locard’s Principle:
the perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence
Hair/Fibers
Fingerprints
Blood (due to contact---not from wounds)
Footprints/Impressions
Paint/Chemicals
Body Fluids

49. Examples of Associative Evidence
Associative Evidence—items that may associate a victim or suspect with a scene or each other; ie, personal belongings
Identification Cards
Security Camera Footage
Receipts
Personal Belongings
Jewelry etc…

50. COLLECTING AND PACKAGING EVIDENCE
Why do you think it is important to collect and package evidence correctly?
What could happen to evidence if it isn’t handled correctly?
What type of errors do you think investigators typically make?

51. COLLECTING AND PACKAGING EVIDENCE
One individual should be designated as the evidence collector to ensure that the evidence is collected consistently
Each item must be placed in a separate container, sealed, and labeled
Most fragile is collected and packaged first
Different types of evidence require specific or special collection and packaging techniques
The body is the property of the coroner or medical examiner. The collection of evidence on the body is done by that department
Should also collect controls from a known suspect or victim (this is a control) to compare to unknown evidence from the crime scene.

52. PACKAGING Blood evidence should be packaged to avoid mold/mildew
Most items should be packaged in a primary container and then placed inside a secondary one.
These are then placed inside other containers such as paper bags, plastic bags, canisters, packets and envelopes depending on the type and size of the evidence.
Blood evidence should be packaged to avoid mold/mildew
Never in plastic-always in paper or sealed test tube
Arson evidence should be in an airtight container
Prevents evaporation of possible fume evidence
Glass evidence should be packaged in a rigid container to avoid cuts

53. CHAIN OF CUSTODY
There must be a written record of all people who have had possession of an item of evidence.
The evidence container must be marked for identification
The collector’s initials should be placed on the seal
If evidence is turned over to another person, the transfer must be recorded.

54. Chapter 3
THE CRIME SCENE
A crime scene is anywhere evidence can be found that is associated with a case
Primary Crime Scene- where crime was committed
Secondary Crime Scene- evidence found in a place where crime was not committed
Example: Where the victim was murdered is the primary crime scene, where the perpetrator moved the body after is the secondary crime scene
Kendall/Hunt

55. CRIME SCENE TEAM
A group of professional investigators, each trained in a variety of special disciplines.
Team Members
First Police Officer on the scene
Medics (if necessary)
Investigator(s)
Medical Examiner (if necessary)
Photographer and/or Field Evidence Technician
Lab Experts

56. FIRST OFFICER ON THE SCENE
A Assess the crime scene and assist those hurt
D Detain the witness
A Arrest the perpetrator
P Protect the crime scene
T Take notes

57. PROCESSING A CRIME SCENE
Isolate and secure the scene
Document the scene
Search for evidence
Collect and package evidence, maintaining the chain of custody
Submit evidence to the crime lab

58. CRIME SCENE SURVEY
Walk-through—performed by the crime scene investigator, the first officer and sometimes the lead detective
Purpose:
Mentally prepare a reconstruction theory
Note any transient or conditional evidence that could change over time.
Note weather conditions
Note points of entry or exit, as well as paths of travel within the crime scene
Record initial observations of who, what, where, when, and how
Identify special needs within the crime scene for personnel, precautions or equipment and notify superior officers or other agencies

59. DOCUMENTATION
Notes—date and time, description of the location, weather and environmental conditions, description of the crime, location of the evidence relative to other key points, the names of all people involved, modifications that have occurred and other relevant information
Photography—photos of scene and surroundings, mid-range to close-up photos with various angles of each piece of evidence, photos as viewed by any witnesses.
Sketches—inclusion of date, time, scale, reference points, distance measurements, names of investigators, victims, suspects, and a legend (key)
Videography—allows narration (non-subjective) to be included

60. SEARCH METHODS Line or strip method—best in large, outdoor scenes
Grid method—basically a double-line search; effective, but time-consuming
Zone method—most effective in houses or buildings; teams are assigned small zones for searching
Wheel or ray method—best on small, circular crime scenes
Spiral method—may move inward or outward; best used where there are no physical barriers

61. CRIME SCENE RECONSTRUCTION
Stages
Data collection
Hypothesis formation
Examination, testing and analysis
Determination of the significance of the evidence
Theory formulation

62. CRIME SCENE SKETCHES -Drawn to Scale -All evidence is labeled
4358 Rockledge Dr, St. Louis, Mo.
Date: August 14, 2005
Time: 11:35 am
Homicide
Ann Wilson
-Drawn to Scale
-All evidence is labeled
-Measurements are given
-Sketch Information Recorded

63. Step 1: Draw a rough outline of the area- include windows (represented by the rectangles) and doors (represented by openings in the outline)
Step 2: Measure the room or space in which the crime occurred. Label the dimensions on the sketch

64. Step 3: Sketch in the furniture and location of evidence using basic shapes
Step 4: Label each item in the diagram with a number or letter, then write the name in a key.

65. Step 6: MEASURING FROM FIXED POINTS
Step 5: Label the diagram with the date, time, location, and victim’s name (if known)
Note: An unknown victim is commonly given the name of John Doe or Jane Doe
Step 6: MEASURING FROM FIXED POINTS
Make two measurements from fixed (not moveable) points to each piece of evidence
These measurements are noted on a separate document, and not on actual sketch
Put on back of sketch
See Board

66. Examples OF sketches