Post on 13-Dec-2015
Introduction to Forensics
September 7, 2005
Mr. Schildknecht
SUPA Forensics
The Science Behind Catching Criminals
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
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.
History
• Alphonse Bertillon (1853-1914)First scientific system of personal
identificationDeveloped the science of
anthropometry, a systematic procedure of taking a series of body measurements as a means of distinguishing one individual from another
History, Con’t
• Edmond Locard (1877 -1966)Locard’s 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.
Organization of Crime Labs
• General OrganizationNo nationally organized system—
crime labs mirror the fragmented law enforcement structure that that exists on national, state, and local levels
• National Levelfour major federal crime labs, FBI,
DEA, ATF, US Postal
Organization, Con’t
• FBI (Department of Justice)Largest crime lab in the worldBroad 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
Organization, Con’t
• 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
Organization, Con’t
• State LevelMost 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.
Organization Con’t
• Local LevelLocal labs provide services to
county and municipal agencies.Generally, they operate
independently of state labs and are financed by local government.
Functions of the Forensic Scientist
• Analysis of Physical EvidenceApplies 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
Functions Con’t
• Provision of Expert TestimonyMay be required to testify with
respect to methods and conclusions at a trial or hearing.
• Furnish TrainingTrain law enforcement in the proper
recognition, collection, and preservation of physical evidence
Scientific Admissibility
• Frye StandardCourt 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
Admissibility, Con’t
• Daubert Standard Court decides on the admissibility of
science in the courtroom “General Acceptance” is not an absolute
prerequisite for admissibilityTo ascertain the veracity of scientific
evidence presented the judge should use the following areas of inquiry
Daubert Criteria
• Technique or theory can be (and has been) tested
• Technique or theory has been subject to peer review and publication
• Technique’s potential rate of error• Existence and maintenance of standards
controlling the technique’s operation• Method or theory has attracted widespread
acceptance within a relevant scientific community