1. CRIME SCENE INVESTIGATION AND EVIDENCE COLLECTION

4. document

5. and collect evidence at the scene of a crime.Solving the crime will depend on piecing together the evidence to form a picture of what happened at the crime scene.

6. *Physical Evidence-encompasses any & all objects that can establish that a crime has been committed or can link a crime & its victim or its perpetrator. Evidence can be classified as direct or circumstantial evidence.

7. *Direct evidenceevidence that (if true) proves an alleged fact; includes first hand observations such as eyewitness accounts. Confessions are also considered direct evidence. Also police dash videos *Circumstantial evidence is indirect evidence that can be used to imply a fact but that does not directly prove it; but circumstantial evidence at a crime scene may provide a link between the crime scene and the suspect. Circumstantial evidence can be either physical or biological in nature.

9. footprints

10. shoe prints

11. tire impressions

12. tool marks

13. fibers

14. weapons

15. bullets

17. hair

18. plant parts

21. Soil

22. Hairs

24. Handwriting

25. Bullets (striations)

26. Toolmarks (striations)

27. Shoeprints (wear patterns)

28. Tire prints

30. The first person to note this condition was Dr. Edmond Locard, director of the world’s 1st forensic laboratory in Lyons, France. Locard’s Exchange Principlestates that when a person comes into contact with an object or another person, a cross transfer of physical evidence can occur. The exchanged materials indicate the two objects were in contact. The second part of Locard’s Principle states that the intensity, duration and nature of the materials in contact determine the extent of the transfer.

31. The Seven S’s of Crime-Scene Investigation Securing the scene Separating the witnesses Scanning the scene Seeing the scene Sketching the scene Searching for evidence Securing & Collecting evidence

36. The 1st priority at the crime scene is to preserve life & help any living victims. The 2nd priority is to detain & question any suspects & remove them from the scene. Potential witnesses should be detained, separateddone to avoid witnesses working together to create a story (collusion) & questioned. Police must secure the crime scene to prevent traffic through the area that may destroy or contaminate evidence. In order to be useful, evidence at a crime scene must be preserved & recorded. Good record keeping is essential

37. Secure & Isolate the Crime Scene Destruction or altering of P.E. can occur when a crime scene is not properly secured & documented. Investigators only have a limited amount of time to work a crime site in its untouched state. The opportunity to record the CS in its untouched state must not be lost.Responsibilities of 1st Officer arriving:1. obtain medical assistance for anyone in need2. arrest any perpetrators3. exclude all unauthorized personnel4. isolate the area

38. Once the C.S. has been secured the lead investigator will:1. determine the boundaries of the C.S.2. establish the perp’s path of entry & exit3. proceed w/ an initial walk-through4. develop a strategy for examining and documenting the entire C.S.5. Determination of primary & possible secondary crime scenes6. Obvious evidence documented & photographed.

39. *Primary crime scenethe location where the crime took place *Secondary crime scene a location other than the primary crime scene, but that is in some way related to the crime, where evidence is found

40. Record the Scenethe time a C.S. remains untouched is limited; therefore timely recording of the C.S. is essential for the investigation and any subsequent trialsUse of Photography, sketches, & notes are the 3 methods for crime-scene recording.

41. Photography an unaltered C.S. is most important; objects must NOT be removed until they have been photographed from all angles. if any object is moved or removed from the C.S. it should be noted – under NO circumstance should it be reintroduced C.S. photos should include not only the immediate scene but also: all relevant angles adjacent areas close-ups of victim’s relative position in the scene and any injuries possible weapons the area under the body evidence is photographed as it is found and if size is significant, a point of reference should be included in the photo New Technology digital photos allow near three-dimensional panoramic views of the crime scene videotaping the C.S. is rising in popularity – the investigator must narrate as he/she records the scene

42. "Golden Rule" of Crime Scene Investigation/Management "Never touch, change, or alter anything until it has been documented, identified, measured, and photographed . . . when a body or article has been moved, it can never be restored to its original position."

43. Sketches Once photos have been taken, the crime-scene investigator sketches the scene * Rough Sketcha draft representation of all essential info & measurements at a crime scene. This sketch is drawn at the crime scene. It shows dimensions & location of objects. On the sketch, North should be labeled. Objects are located in the sketch by distance measurements from 2 fixed points. All measurements are made w/ a tape measure. The simplest way to designate an item is to assign it a # or letter. A legendmust be placed below the sketch. *Finished Sketcha precise rendering of the crime scene, drawn to scale.

46. time of discovery

47. who found it

48. who packaged and marked it

49. disposition of item after being collected

50. must be detailed enough to refresh one’s memory months  years after processing

52. Crime Scene Search Patterns SPIRAL GRID LINEAR

53. Securing & Collecting Evidence 1. Evidence can be massive to microscopic 2. may only be detected in a crime lab ex. traces of blood on clothing, hair and fibers from vacuum sweeps 3. it is sometimes necessary to confiscate clothing from victim and perp Critical areas should be vacuumed; sweepings from different areas must be kept separate 5. finger nail scrapings must also be taken from suspects and victims

55. transferred to moistened swab

56. cut out the area of object8. Each item must be kept separately

58. Item inventory #

59. Description of the evidence

60. Name of suspect

61. Name of victim

62. Date & time of recovery

63. Signature of person recovering the evidence

65. Obtaining Standard/Reference Samples 1. Collect evidence from suspects and victims that are similar to the P.E. collected @ the scene paint from vehicles hair or blood 2. buccal swab 3. substrate control

66. Reference Samples * control samplemust be obtained from victim for purposes of exclusion *standard/reference samplephysical evidence whose origin is known, that can be compared to crime scene evidence. The presence of reference samples greatly facilitates the work of the forensic scientist. Ex: blood or hair from possible suspects to be compared to crime scene evidence. * Buccal swabswab of inner portion of cheek, performed to collect cells for use in determining DNA profiles * Substrate controluncontaminated surface material close to an area where phys evidence has been deposited; used to ensure that the surface on which a sample has been deposited does not interfere w/ lab tests

68. Entire object should be sent to the lab.

69. Each different item must be placed in separate containers. Packaging evidence separately prevents cross contamination.

70. Unbreakable plastic pill bottles excellent containers for hair, fiber, glass evidence

72. Wet evidence should NEVER be packaged in plastic containers while wet.

73. Bloodstained materials should NOT be stored in airtight containers b/c accumulation of moisture may encourage the growth of mold; in these instances wrapping paper, manila envelopes or brown paper bags are used.

74. All items of clothing must be air dried & place in individual separate bags.