Introduction to Forensic Science

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Chapter 1

• Introduction to Forensic Science

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Forensic Science

• Application of science to law
• Begins at crime scene
• Also known as Criminalistics

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History of Forensics
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Alphonse Bertillon

• Father of Criminal Identification
• Developed ANTHROPOMETRY

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Anthropometry

• Series of body measurements to distinguish
  between individuals

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Francis Galton

• Studied fingerprints how to classify them

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Calvin Goddard

• Firearms examiner
• Studied bullet comparison
• (Done today with a comparison microscope)

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Edmond Locard

• Started the 1st crime lab (France)
• Developed the Exchange Principle

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Locards Exchange Principle

• When 2 objects come into contact, there is an
  exchange of materials between them
• (Cross-transfer of evidence)
• Criminals can be connected to a crime by
  particles carried from the crime scene

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Crime Laboratories

• A. National
• B. State
• C. Local

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National Labs (4)

1. Federal Bureau of Investigation (FBI ?
   largest lab in the world)
2. Drug Enforcement Administration (DEA)
3. Bureau of Alcohol, Tobacco, Firearms,
   Explosives (ATF)
4. U.S. Postal Inspection Service

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State Labs

• Service the state as well as
• local communities that cannot
• afford their own crime lab

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Local Labs

• Service counties municipal (cities) agencies
• Financed by local government
• Nassau Suffolk County Crime Labs

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Basic Crime Lab Services

1. Physical Science Unit
2. Biology Unit
3. Firearms Unit
4. Document Examination Unit
5. Photography Unit

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Physical Science Unit

• Uses chemistry, physics, and geology to identify
  compare evidence

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Biology Unit

• Examines blood other body fluids
• DNA profiles
• Compares hair fibers
• Examines botanical materials (plants/wood)

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Firearms Unit (Ballistics)

• Examines firearms, discharged bullets, cartridge
  cases, shotgun shells
• Searches clothing for gunpowder residue
• Determines distance a weapon was fired from

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Document Examination Unit

• Studies handwriting or typewriting
• Analyzes paper ink
• Examines indented writings burned documents

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Photography Unit

• Examines records physical evidence
• Only black white photos are shown to jurors

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Optional Services

1. Toxicology Unit ? poisons/drugs
2. Latent Fingerprint Unit
3. Polygraph Unit ? lie detector
4. Voiceprint Analysis Unit
5. Evidence Collection Unit ? CSI

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Evidence the Courts
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Frye vs. United States (1923)

• Rejected lie detector evidence
• Scientific techniques, procedures, principles
  must be GENERALLY ACCEPTED by majority of
  scientific community

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Daubert vs. Merrell Dow Pharmaceuticals (1993)

• GENERAL ACCEPTANCE is no longer absolute
• Trial judge will act as GATEKEEPER ? deciding
  whether evidence is admissible or not

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The Expert Witness

• A person with knowledge that is not expected from
  the average individual
• This is acquired through experience, training,
  education, or a combination of all 3

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Testimony

• Ordinary witnesses cannot must not give their
  opinions ? just FACTS
• Expert witnesses can give their opinions based on
  scientific facts (but cant be biased to either
  side)

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• Other Areas of Forensic Science

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Forensic Pathology

• Investigates sudden, unnatural, unexplained, or
  violent deaths
• Tries to answers Who? What? When? Why? How?
• Via Autopsy

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Types of Death

• Natural
• Accidental
• Homicide
• Suicide
• Undetermined????

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Estimating Time of Death
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Rigor Mortis

• Muscles shorten body stiffens
• Appears within 24 hours
• Disappears within 36 hours

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Livor Mortis

• Blood settles to areas closest to ground
• Skin turns a blue/purple color

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Algor Mortis

• Body starts to lose heat
• 1-1.5F per hour until room or outside
  temperature is reached

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Potassium Levels

• Rise in ocular (eye) fluid after death
• Time of death estimated by amount of potassium
  present

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Forensic Anthropology

• Identifies examines human skeletal remains
• Determines race, sex, age, injuries
• Creates facial reconstructions

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Forensic Entomology

• Studies insects their relation to death
• Blow flies lay eggs ? maggots

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Forensic Psychiatry

• Determines if people are competent enough to make
  decisions or stand trial
• Develop behavioral profiles

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Forensic Odontology

• Studies teeth bite marks
• Useful when a body is unrecognizable

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Forensic Engineering

• Determines how a crime happened who is
  responsible
• Accident reconstruction