Principles of Forensic Identification Science (From Handbook of Criminal Investigation, P 303-337, 2007, Tim Newburn, Tom Williamson, and Alan Wright, eds. -- See NCJ-220829)

• NCJ Number: 220837
• Author(s): A.P.A. Broeders
• Date Published: 2007
• Length: 35 pages
• Sale Source: Willan Publishing
• Publication Format: Book Chapter
• Publication Type: Instructional Material
• Language: English
• Country: United Kingdom

Annotation

This chapter examines the nature and reliability of forensic sciences that trace biological material left at a crime scene to specific individuals.

Abstract

Forensic identification science involves an analysis of the characteristics of trace material found at a crime scene and the development of a probability estimate that the material was left at the scene by a particular person. It is a misconception however, that forensic science can provide an absolute determination that a particular person deposited a given sample of trace evidence at a location. Although fingerprint and DNA analysis can show a high probability that a particular individual left particular trace evidence at a scene, neither science can make absolute claims of identification. Currently, DNA analysis is the only type of forensic analysis that can calculate the probability that a particular DNA sample was left by a specific individual. Forensic identification scientists are ultimately making a subjective judgment in reaching a categorical decision about the identity of a source for trace evidence; however, there is no absolute scientific certainty of the source. There is always some degree of chance that another unknown person with characteristics very similar to the known suspect could have left the trace material. It is up to the trier of fact (judge or jury) to determine whether there is reasonable doubt, considering all the evidence presented, that the defendant left the trace evidence at the scene. 15 notes and 56 references