Forensic Techniques

1
Forensic Techniques
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What is Forensic Science?

• Forensic comes from the Latin word forensis.
• It means for public discussion or debate.
• Forensic science is science used in public, in a
  court or in the justice system. Any science, used
  for the purposes of the law, is a forensic
  science.

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Forensic Scientists

• Television enhances the image of forensic
  science.
• Forensic scientists are involved in all aspects
  of criminal cases.
• The forensic scientist's goal is to use all
  available scientific information to determine the
  facts and, subsequently, the truth.
• The forensic scientist might determine
• The validity of a signature on a will,
• If a corporation is complying with environmental
  laws,
• The origin of physical evidence at a crime scene.

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Forensic Scientists

• The facts developed by forensic scientists are
  based on scientific investigation, not
  circumstantial evidence or the sometimes
  unreliable testimony of witnesses.
• The work of the forensic scientist can prove the
  existence of a crime or makes connections to a
  crime.
• The forensic scientist provides information and
  expert opinion to investigators, attorneys,
  judges, and juries which is helpful in
  determining the innocence or guilt of the
  accused.
• Forensic scientists work closely with police
  officers, sheriff's deputies, prosecuting and
  defense attorneys, DEA, CIA, and FBI agents,
  immigration workers, and crime scene
  investigators, to name a few.

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Techniques

• Forensic scientists use a variety of techniques
  in their investigations.
• The next 8 slides provide examples of forensic
  techniques.

6
Firearms and Toolmarks

• Typically, this includes matching bullets to the
  gun that fired them.
• Toolmark identification involves the identifying
  characteristics between tools, such as a pry bar,
  and the object on which it is used, such as a
  door frame.
• Also included in the category are explosives and
  imprint evidence.

7
Forensic Profiling

• When a specially trained psychiatrist or
  investigator can examine certain crime scenes to
  come up with a personality profile of the
  offender.  

8
Document Examination

• This discipline involves all special
  relationships that may exist between document and
  inscription and how it relates to a person or
  sequence of events.
• This includes forgery, counterfeiting, and
  handwriting analysis.

9
Autopsy

• Done by a medical examiner
• To determine cause of death
• Includes external exam and photos
• Followed by extensive internal exam
• Organs are removed, weighed and examined
• Tissues and fluids are analyzed for
  abnormalities, presence of drugs, etc.

10
DNA Typing

• DNA code varies from one individual to the next
• Scientists can link a strand of DNA to an
  individual
• DNA can be identified from hair, blood, or body
  fluid stains
• Provides powerfully compelling evidence

11
Forensic Anthropology

• Examination of skeletal remains
• Tells if male or female, how the person lived,
  past illness or debilitation, clues to occupation
• Bones can tell us
• Age at time of death
• Gender
• Race
• Height

12
Odontology

• Teeth no other body part lasts longer
• In fires, often the only thing remaining
• No two people have identical teeth
• Dental records are needed to compare to the
  evidence
• Teeth useful in determining a subjects age

13
Blood

• Chemical test can determine if substance (stains)
  is really blood
• Another test determines if it is animal or human
  blood
• Can determine gender from blood evidence