1. CSI vs. “CSI” 1. How is real CSI similar to TV CSI?
2. How is real CSI different from TV CSI?
3. Does real CSI typically handle an entire case from start to finish?
List a few things from CSI that are possible and not possible from your own opinion.
Possible Not Possible

2. Unit 2 – Crime Scene Investigation and Evidence Collection

3. How is it possible to identify the person who committed a crime?

4. Crime Scene Investigation:
Defined: the goal of a crime scene investigation is to recognize, document, and collect evidence at the scene of a crime. Solving the crime will then depend on the piecing together the evidence to form a picture of what happened at the crime scene.

5. Principle of Exchange
Established by Dr. Edmond Locard, the LOCARD principle states:
When a person comes in contact with an object or another person, a cross-transfer of physical material can occur
Studying the material can determine the nature and duration of the transfer
To a forensic examiner, these materials that are cross transferred constitute what is called trace of evidence.
What are some Examples????

6. A Few Examples Include Pet hair on your clothes or rug
Hair fibers on clothing
Fingerprints on glass
Soil tracked into your house on your shoes
A drop of blood on a T-shirt
A used facial tissue
Paint transfer from a car to bicycle
Broken glass
and much more.

7. Hair Fibers

8. Fibers

9. Automobile Paint Chips

10. Soil Sample

11. Polymers

12. Footprint

13. Ted Bundy’s Bite Marks

14. Ted Bundy’s Head after the Electric Chair
Interesting Side Note!

15. Types of Evidence

16. Types of Evidence
Direct Evidence: includes first hand observations such as eyewitness account or police dashboard video cameras.
Example: Eyewitness, Photos, Video Tape

17. Eyewitnesses Question:
Should eyewitness testimony be enough to make a conviction in a criminal case?
Why or Why Not
Don't always trust television!.. Crime shows love to show the compelling "eyewitness" testimony.  Most laypeople believe that an eyewitness is the cornerstone of a criminal case.  However, police officers and courts  rarely use eyewitnesses.  Why?  Because the human mind can only focus on one or two things at at any one time.

18. Magic

19. Circumstantial Evidence: is indirect evidence that can be used to imply a fact but that does not directly prove it. No one, other than the suspect and victim, actually sees when circumstantial evidence is left at the crime scene. This evidence can be physical or biological in nature.
Example: finding a gun at the suspect’s house, bloody knife, fingerprints, etc.

20. Trace Evidence Trace evidence is a type of circumstantial evidence.
Examples:
Animal or Human Hair
Fingerprints
Soil of Plant Material (Pollen)
Body Fluids (Mucus, semen, saliva, or blood)
Fiber or debris from clothing
Paint Chips, broken glass, chemicals

21. Types of Circumstantial Evidence
Physical: Evidence not from living organisms
Examples: impressions such as fingerprints, footprints, shoe prints, tire impressions, and tool marks, gun, knife, car(not paint), pan.
Biological: From living organisms
Examples: body fluids, hair, plant parts, and natural fibers.

22. Explain why this would or would not be trace evidence.

23. 2 Classifications of Evidence
Class Evidence: narrows an identity to a group of persons or things. Knowing the ABO blood type of a sample of blood type that may have been there, excludes others.
Individual Evidence: narrows an identity to a single person or thing. Individual evidence typically has such a unique combination of characteristics that it could only belong to one person or thing, such as a fingerprint.

24. Do Now: On a separate sheet of paper to hand in
Define and list an example of each.
1. Direct Evidence
2. Biological Evidence
3. Physical Evidence
4. Class Evidence
5. Individual Evidence

25. Who is involved in a crime-scene investigation?

26. Police Officers: are usually the first ones to arrive.
Crime-scene Investigators: document the crime scene in detail and collect physical evidence.
Medical Examiners/Coroners: may be necessary to determine the cause of death.
Detectives: look for leads to interview witnesses’.
Specialists: insect biologists (entomologists), forensic psychologists, etc.

27. The S’s of Crime-Scene Investigation

28. The Seven S’s of Crime Scene Investigation
Secure the scene
Separate the witnesses
Scan the scene
Seeing the scene
Sketch the scene
Search for evidence
Secure the collected evidence

29. 1. Securing the Scene First-responder: First officer at the scene
Responsible for safety to all the individuals
Preservation of evidence.
Must start a security log and collect any other important information

30. 2. Separating The Witnesses
Why do you think it is important to separate the witnesses????

31. 2. Separating The Witnesses
Witnesses should not be allowed to talk to each
other because their accounts will be compared.
Questions to be asked:
When did the crime occur?
Who called in the crime?
Who is the victim?
Can the perpetrator be identified?
What did you see happen?
Where were you when you observed the crime scene?

32. Write your own example of a primary and secondary crime scene
3. Scanning The Scene
Forensic examiners need to scan the scene to determine where photos should be taken. A determination may be made of a primary crime-scene and secondary crime scene.
Write your own example of a primary and secondary crime scene
Example: Where robbery took place is primary and where the suspect lives is the secondary crime-scene.

33. 4. Seeing The Scene
A view of the crime scene should be taken from several different angles and distances. Several close-up photos of any evidence and bodies should be taken.

35. Wide angle lenses are used to distort the truth or emphasis it

36. Details preserved

37. 5. Sketching The Scene
An accurate rough sketch of the crime scene is made, noting the position of the body (if any) and any other evidence. All objects should be measured from two immovable landmarks.

38. Blank Crime-Sketch Form

41. Nirvana

42. 6. Searching for Evidence
These patterns are systematic, ensuring that no area is left unsearched.
Grid
Linear
Quadrant or Zone
Spiral

43. Crime-Scene Search Patterns

44. 7. Securing and Collecting Evidence
All evidence needs to be properly packaged, sealed, and labeled. Specific procedures and techniques for evidence collection and storage must be followed. An evidence log and a chain of custody document must be attached to the evidence container. The evidence log should contain all pertinent information, including:
Case number, item inventory number, description of the evidence, name of suspect, name of victim, date and time of recovery, signature of person recovering the evidence, signature of any witnesses present during collection.

46. Cast’s of Physical Evidence
Blood Spatter Analysis

47. Packaging Evidence
Crease a clean paper and place evidence in the X position
Fold in the left and right sides, and then fold in the top and bottom
Put the bindle into a plastic or paper evidence bag affixing a seal over the opening
Write your name on the seal

48. Paper Bindle Folds

49. Evidence ID Forms

50. Evidence Bag
Maintaining a chain of custody log is essential to present credible evidence in court

51. What determines the type and manner of collecting and preserving physical evidence?
The nature of the evidence

52. Q. What type of evidence is to be retrieved from a deceased victim for examination in the crime laboratory?
Clothing
Fingernail scrapings
Head and pubic hairs
“Orifice” swabs
Bullets
Hand swabs for gunshot residues

53. Forensic Science: Fundamentals & Investigations, Chapter 2
Chain of Custody
-Bag the evidence -Add identification -Seal it -Sign it across the sealed edge
-Sign over to a lab technician -Open bag on non-sealed edge
-Return items to the evidence bag -Seal evidence bag in another bag -Sign the evidence log
Forensic Science: Fundamentals & Investigations, Chapter 2

54. Analyze the Evidence
Facts result from collected evidence processed by the forensic lab
Lead detectives aim to see how facts fit into the crime scenario

55. Analyze the Evidence
Lab results can:
Show reliability of witness accounts
Establish the identity of suspects or victims
Show suspects to be innocent or link them with a scene or victim

56. Crime Scene Reconstruction
Crime scene reconstruction involves:
Forming a hypothesis of the sequence of events
From before the crime was committed through its commission

57. Staged Crime Scenes
When lab results don’t match up with the testimony of witnesses
Common examples:
Staging a fire—to cover bankruptcy
Staging a suicide—to cover a murder
Staging a burglary—to collect insurance money

58. Staged Crime Scenes Was the crime scene staged? Consider:
Does the type of wound match the weapon?
Could the wound be easily self-inflicted?
What were the mood and actions of the victim before the event?
What were the mood and actions of the suspect before the event?

59. Summary
Locard’s exchange principle:
Contact between people and objects can transfer material that can determine the nature and duration of the transfer
Evidence can be direct or indirect
Physical or biological traces
A crime scene investigation team consists of police, detectives, crime scene investigators, medical investigators, and specialists.

60. Investigations consist of recognizing, documenting, and collecting evidence.
First responding officers identify the extent of the crime scene, secure it, and segregate witnesses.
Crime scene investigators document the crime scene.
Evidence is collected, packaged, and labeled.
The evidence is analyzed and interpreted to fit the crime scenario.