Introduction to Forensics

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September 2007
Introduction to Forensics
The Science Behind Catching Criminals
Mr. Schildknecht SUPA Forensics Used with
permission
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Overview

• Definition of Forensic Science
• Scope
• History and Development of Forensics
• Organization of a Crime Laboratory
• Functions of the Forensic Scientist
• Analysis of Physical Evidence
• Provision of Expert Testimony
• Furnishing Training
• Scientific Admissibility

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Definition and Scope of Forensic Science

• Forensic science is the application of science to
  those criminal and civil laws that are enforced
  by police agencies in a criminal justice system.

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History

• Alphonse Bertillon (1853-1914)
• First scientific system of personal
  identification
• Developed the science of anthropometry, a
  systematic procedure of taking a series of body
  measurements as a means of distinguishing one
  individual from another

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Bertillon Measurements
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History, Cont

• Edmond Locard (1877 -1966)
• Locards Exchange Principle the exchange of
  materials between two objects that occurs
  whenever two objects come in contact with one
  another. A cross-transfer of evidence occurs.

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Organization of Crime Labs

• General Organization
• No nationally organized systemcrime labs mirror
  the fragmented law enforcement structure that
  that exists on national, state, and local levels
• National Level
• four major federal crime labs, FBI, DEA, ATF, US
  Postal

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Organization, Cont

• FBI (Department of Justice)
• Largest crime lab in the world
• Broad investigative powers
• DEA (Drug Enforcement Agency)
• Responsible for the analysis of drugs seized in
  violation of laws regulating the production,
  sale, and transportation of drugs

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Organization, Cont

• ATF (Bureau of Alcohol, Tobacco, Firearms, and
  Explosives)
• Responsible for the analysis of alcoholic
  beverages, weapons, and explosives in conjunction
  with the Gun Control Act and Organized Crime
  Control

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Organization, Cont

• State Level
• Most state governments maintain a lab to service
  state and local law enforcement
• Some larger cities maintain their own crime lab,
  usually under the direction of local police dept.
  

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Organization Cont

• Local Level
• Local labs provide services to county and
  municipal agencies.
• Generally, they operate independently of state
  labs and are financed by local government.

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Services of the Crime Lab
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Functions of the Forensic Scientist

• Analysis of Physical Evidence
• Applies the principles and techniques of the
  physical and natural sciences to the analysis of
  evidence
• Must be aware of the demands and constraints of
  the judicial system
• Scientific procedures and techniques must satisfy
  the criteria of admissibility established by the
  courts

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Functions Cont

• Provision of Expert Testimony
• May be required to testify with respect to
  methods and conclusions at a trial or hearing.
• Furnish Training
• Train law enforcement in the proper recognition,
  collection, and preservation of physical evidence

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Scientific Admissibility

• Frye Standard
• Court must decide if a questioned procedure,
  technique, or principles are generally accepted
  by a meaningful segment of the scientific
  community
• In practice, this has meant providing experts to
  testify that the procedure is generally accepted
• Courts have also taken note of books, papers, and
  past judicial decisions in this regard

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Admissibility, Cont

• Daubert Standard
• Court decides on the admissibility of science in
  the courtroom
• General Acceptance is not an absolute
  prerequisite for admissibility
• To ascertain the veracity of scientific evidence
  presented the judge should use the following
  areas of inquiry

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Daubert Criteria

• Technique or theory can be (and has been) tested
• Technique or theory has been subject to peer
  review and publication
• Techniques potential rate of error
• Existence and maintenance of standards
  controlling the techniques operation
• Method or theory has attracted widespread
  acceptance within a relevant scientific community