Forensic Biology by Richard Li

1
Forensic Biologyby Richard Li

• Chapter 3 Crime Scene Investigation and
  Laboratory Analysis of Biological Evidence

2
Forensic Investigations Involving Biological
Evidence

• Requires
• Crime scene examination
• Scene security, documentation, collection and
  preservation of evidence
• Laboratory analysis
• Utilizes scientific techniques for evidence
  examination, identification of biological fluids,
  and the comparison of individual characteristics

3
Crime Scene Investigation

• Protecting and securing the scene
• Duty of the first officer on the scene
• Only authorized personnel
• Use log sheet
• Obtain medical attention if needed
• Proper supplies and devices must be utilized
• E.g. Disposable suits, face mask, disposable
  gloves and booties

4
Crime Scene Investigation

• Documentation
• Sketch
• Rough and Finished
• Photographs
• Use photo log sheet
• Use scale
• Video

5
Crime Scene Investigation

• Chain of Custody- lists custody information at
  every point in time when evidence is handled or
  transferred

6
Crime Scene Investigation

• Recognition of probative biological evidence
• Corpus delicti evidence
• Evidence that a crime has occurred
• Context-dependent
• Victim-to-perpetrator linkage evidence
• Victim-to-scene linkage evidence
• Perpetrator-to-scene linkage evidence
• Case-to-case linkage evidence
• Modus operandi
• Ted Bundy

7
Ted Bundy

• Serial killer
• Murdered more than 30 women may have been more
  than 100 (1972-78)
• Modus operandi
• Often approached victims in public places
• Used various ruses to gain their trust
• Pretended to have a broken leg (fake cast and
  crutches)
• Posed as police officer, fireman
• Targeted middle-class, young females (15-25)
• Hand-cuffed and then raped and bludgeoned victims
• Dumped bodies

8
Mug shot taken after arrest in Utah, 1975
Items taken from Bundys Volkswagon, Aug 16 1975
9
Bundy victims 1972

• January 4 "Joni Lenz" (pseudonym) (survived).
  University of Washington first-year student who
  was bludgeoned in her bed as she slept.
• February 1 Lynda Ann Healy (21). Bludgeoned
  while asleep and abducted from the house she
  shared with other female University of Washington
  students.
• March 12 Donna Gail Manson (19). Abducted while
  walking to a jazz concert on the Evergreen State
  College campus, Olympia, Washington. Bundy
  confessed to her murder, but her body was never
  found.
• April 17 Susan Elaine Rancourt (18). Disappeared
  as she walked across Ellensburg's Central
  Washington State College campus at night.
• May 6 Roberta Kathleen "Kathy" Parks (22).
  Vanished from Oregon State University in
  Corvallis, Oregon while walking to another
  dormitory to have coffee with friends.
• June 1 Brenda Carol Ball (22). Disappeared from
  the Flame Tavern in Burien, Washington.
• June 11 Georgeann Hawkins (18). Disappeared from
  behind her sorority house, Kappa Alpha Theta, at
  the University of Washington.

10
Bundy victims 1974

• July 14 Janice Ann Ott (23) and Denise Marie
  Naslund (19). Abducted several hours apart from
  Lake Sammamish State Park in Issaquah,
  Washington.
• September 2 Unknown teenage hitchhiker, Idaho.
  Confessed before his execution. No remains found.
  
• October 2 Nancy Wilcox (16). Disappeared in
  Holladay, Utah. Her body was never found.
• October 18 Melissa Anne Smith (17). Vanished
  from Midvale, Utah, after leaving a pizza parlor.
  
• October 31 Laura Aime (17). Disappeared from a
  Halloween party at Lehi, Utah.
• November 8 Carol DaRonch (survived). Escaped
  from Bundy by jumping out from his car in Murray,
  Utah.
• November 8 Debra "Debby" Kent (17). Vanished
  from the parking lot of a school in Bountiful,
  Utah, hours after Carol DaRonch escaped from
  Bundy. Shortly before his execution, Bundy
  confessed to investigators that he dumped Kent at
  a site near Fairview, Utah. An intense search of
  the site produced a human patella (knee cap),
  which matched the profile for someone of Kent's
  age and size. DNA testing has not been attempted.

11
Crime Scene Investigation

• Locard Exchange Principle
• Cross-transference of evidence occurs when a
  perpetrator has any physical contact with
  something or someone else

12
Crime Scene Investigation

• Searches
• Alternate Light Source (ALS)
• Types
• Spiral
• Strip (parallel)
• Grid
• Quadrant/Zone

13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
Crime Scene Investigation

• Collection
• Only done after documentation is complete
• Consider collecting entire item if small enough
  or mobile sometimes may have to collect large
  item (e.g. car see Bundys Volkswagon next
  slide)
• Considerations
• Bloodstain pattern evidence
• Multiple analysis of evidence
• Trace evidence
• Control samples
• Size of the stain
• Wet Evidence

19
Crime Scene Investigation
20
Crime Scene Investigation

• Packaging and Transportation
• Goal protect and preserve evidence
• Avoid heat and humidity
• Package items separately
• Allow wet items to air dry
• Use paper!
• Label properly and seal

21
Laboratory Analysis

• Identification of biological evidence
• Comparison of individual characteristics of
  biological evidence

22
Laboratory Analysis

• Class Characteristics
• Can be placed into a category with other similar
  materials
• Examples?
• Individual Characteristics
• Evidence possesses characteristics that share a
  common origin with a reference sample
• Examples? Proof?

23
Laboratory Analysis

• Final steps
• Reporting results
• Expert testimony