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

Bertillon Measurements

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.

Services of the Crime Lab

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