DNA Profiling and Fingerprinting: Relations between Closure and Controversy

Cornell University, Ithaca NY

Investigators

Abstract

Michael Lynch, Cornell University DNA Profiling and Fingerprinting: Relations between Closure and Controversy This one-year project examines the role of science and technology in criminal justice, specifically the relation of DNA profiling to traditional forms of legal evidence. In criminal investigations, DNA profiling is used to compare bodily traces collected at crime scenes (blood, semen, hair and hair follicles, skin, and cheek cells) with samples taken from suspects. State and national DNA databases are under construction worldwide. When DNA profiling was introduced in the mid-1980s it was called "DNA fingerprinting." The nominal association with the established method of latent fingerprint analysis suggested that the new method would enable investigators to identify unique individuals. However, practical, population genetic, and probabilistic aspects of DNA profiling became controversial in the late 1980s and early 90s. Court disputes and public debates among scientists were popularly dubbed "the DNA wars." Due to a series of legal decisions, technical fixes, and science advisory recommendations, the controversy is now widely declared over, and a post-closure inversion of credibility has occurred. Where DNA "fingerprinting" once borrowed its name and credibility from the older method of fingerprinting, it is now so strongly trusted that it is held as a standard for judging all other forms of criminal evidence, including latent fingerprint evidence. DNA profiling methods are being used to challenge convictions from years past, and this has led to renewed debate about the death penalty and widespread concern about the adequacy of the entire criminal justice process. The PI, Michael Lynch and the co-investigator Simon Cole have conducted extensive research on DNA profiling and latent fingerprint analysis. Both investigators explore how the scientific credibility now ascribed to DNA profiling implicates older forms of criminal evidence, including "common sense" evidence and older forensic practices like fingerprinting. The PIs intend to interview participants in The Innocence Project -- an ongoing effort using DNA profiling to re-open criminal convictions obtained in the pre-DNA era. They draw upon court transcripts, case summaries and participant interviews from recent cases in which fingerprint evidence has been challenged, in order to assess the extent to which the now-established credibility of DNA profiling has led to questioning of traditional forms of evidence. These data are interpreted in light of longer term, international trends in methods of criminal identification. The study contributes to a growing area of S&TS research on the intertwining of law, science, and public values. It also links up with related projects on DNA profiling and criminal databases in the US, Australia, and Europe. The project and its dissemination products have scholarly and educational value by enhancing professional and public insight into some important ethical, legal, and political concerns about the uses of scientific expertise. Some of these concerns are about the impact of DNA databases on civil liberties and privacy, the ability of lay persons to understand and "weigh" scientific and probabilistic evidence, and the possibility that "objective" evidence may obscure the continued importance of critical evaluation of evidence in relation to the overall circumstances of a case.