Transcript Slide 1
Introduction to Forensic Science The Science Behind Catching Criminals Overview • Definition of Forensic Science • History and Development of Forensics • Organization of a Crime Laboratory • Services of the Crime Laboratory • Functions of the Forensic Scientist • Scientific Admissibility Definition and Scope of Forensic Science Forensic science History • Who was the first Forensic Scientist? History • Alphonse Bertillon (1879) Example Developed a criterion for Mugshots and crime scene photos Bertillon Measurements Bertillion con’t • Anthropometry was the standard for criminal identification for 20 years, but there were problems. • What were they? History con’t • Francis Galton (1892) History con’t • Leone Lattes (1915) History con’t • Edmond Locard (1910) Organization of Crime Labs • General Organization 320+ crime labs on the local, state, and federal level • Why? Organization con’t • FBI • DEA Organization con’t • ATF • US Postal Organization con’t • 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. Organization con’t • Local Level Local 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 Services of the Crime Lab Basic Services of the Crime Lab • Physical Science Unit – Uses chemical, physical, and geological techniques to identify and compare crime scene evidence Basic Services con’t • Biology Unit – Analyze: • • • • • DNA Body Fluids Hair Fibers Plants Basic Services con’t • Firearms Unit – Analyze bullets, shells, gunpowder residues, toolmarks Basic Services con’t • Document Examination Unit – Determine authenticity and source of questioned documents • • • • Paper and ink analysis Handwriting Indented writing Obliterations, erasures, charred documents Basic Services con’t • Photography Unit – Record physical evidence at a crime scene Optional Services • • • • • Toxicology Unit Latent Fingerprint Unit Polygraph Unit Evidence Collection Unit Voiceprint Analysis Unit 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 Functions Con’t • 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 Scientific Admissibility • Frye Standard (1923) Frye v. United States Court must decide if a questioned procedure, technique, or principles are “generally accepted” by a meaningful segment of the scientific community Admissibility, Con’t • Daubert Standard (1993) 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 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 Forensic Science Specialties • Pathology • Entomology • Anthropology Specialties con’t • Psychiatry • Odontology • Engineering That’s It