forensic science community. The report concludes that every effort must be made to limit the risk of having the reliability of certain forensic science methodologies judicially certified before the techniques have been properly studied and their accuracy verified.


Science and law always have had an uneasy alliance:

Since as far back as the fourteenth century, scientific evidence has posed profound challenges for the law. At bottom, many of these challenges arise from fundamental differences between the legal and scientific processes. … The legal system embraces the adversary process to achieve “truth,” for the ultimate purpose of attaining an authoritative, final, just, and socially acceptable resolution of disputes. Thus law is a normative pursuit that seeks to define how public and private relations should function…. In contrast to law’s vision of truth, however, science embraces empirical analysis to discover truth as found in verifiable facts. Science is thus a descriptive pursuit, which does not define how the universe should be but rather describes how it actually is.

These differences between law and science have engendered both systemic and pragmatic dilemmas for the law and the actors within it…. Moreover, in almost every instance, scientific evidence tests the abilities of judges, lawyers, and jurors, all of whom may lack the scientific expertise to comprehend the evidence and evaluate it in an informed manner.2

Nowhere are these dilemmas more evident than in decisions pertaining to the admissibility of forensic science evidence proffered in criminal trials.

Forensic science experts and evidence are routinely used in the service of the criminal justice system. DNA testing may be used to determine whether sperm found on a rape victim came from an accused party; a latent fingerprint found on a gun may be used to determine whether a defendant handled the weapon; drug analysis may be used to determine whether pills found in a person’s possession were illicit; and an autopsy may be used to determine the cause of death of a murder victim. In order for qualified forensic science experts to testify competently about forensic evidence, they must first find the evidence in a usable state and properly preserve it. A latent fingerprint that is badly smudged when found cannot be usefully saved, analyzed, or explained. An inadequate drug sample may be insufficient to allow for proper analysis. And, DNA tests performed on a contaminated


Developments in the law—confronting the new challenges of scientific evidence. 108 HARV. L. REV. 1481, 1484 (1995) (hereinafter “Developments in the law”) (footnotes omitted); see also M.A. Berger and L.M. Solan. The uneasy relationship between science and law: An essay and introduction. 73 BROOK. L. REV. 847 (2008).

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement