Forensic Science
•Services in the Crime Lab:
–Physical Science Lab
•Chemistry, physics, geology
•Drugs, glass, paint, explosives, soil
–Biology Unit
•Biologists, biochemists
•DNA, blood (stains), bodily fluids, wood, plant
material
–Firearms Unit
•Firearms, discharged bullets/casings & shells,
ammo
•Analysis of materials for GSR (gunshot residue)
• Document Examination Unit
– Handwriting/type analysis
• Authenticity or source
– Indented writings, other anomalies
• Photography Unit
– All aspects of photography
• Digital, infrared, UV, X-ray (unseen evidence)
• Prepares photos for court
Extras:
• Toxicology Unit (poisons/drugs)
• Latent Fingerprints (hidden)
• Polygraph Unit (interrogation)
• Voiceprint Analysis Unit (telephone or tape
analysis)
• Crime-Scene Investigation Unit (specialize
in evidence collection)
Other specializations in forensics:
• Forensic Pathology (Medical Examiners):
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Who is the victim?
Injuries present
When did the injuries occur?
How were the injuries produced?
CAUSE OF DEATH
• Done by autopsy
• How is time of death determined?:
Determining Time of Death by determining stage of
decomposition:
• Rigor Mortis: Muscles spend excess ATP by becoming
rigid (up to 36 hours)
• Livor Mortis:
– Blood settles to low points of body for first 12 hours after death
– Not affected by points of constriction
• Tell position of body
• Algor Mortis
– Body cools in predictable fashion until ambient (room temp)
– Rule of thumb: 1 -1.5 degrees per hour (norm. cond.)
• Vitreous Humor: Potassium is released into fluid of eye
in a predictable fashion
• Other: amount/cond. of food in stomach
• Forensic Anthropology: Identification and
examination of skeletal remains
• Forensic Entomolgy: Study of insects and
their relationship to investigation
• Forensic Psychiatry: relationship b/n
human behavior and legal precedings
– Competence?
– Profiling
• Forensic Odentology:
 Teeth
– Bite marks in cases
– Last remaining for ID