Our system of criminal justice is best described as a search for the truth. Increasingly, the forensic use of DNA technology is an important ally in that search.

The development of DNA technology furthers the search for truth by helping police and prosecutors in the fight against violent crime. Through the use of DNA evidence, prosecutors are often able to conclusively establish the guilt of a defendant. Moreover, as some of the commentaries suggest, DNA evidence-like fingerprint evidence-offers prosecutors important new tools for the identification and apprehension of some of the most violent perpetrators, particularly in cases of sexual assault.

At the same time, DNA aids the search for truth by exonerating the innocent. The criminal justice system is not infallible, and this report documents cases in which the search for truth took a tortuous path. With the exception of one young man of limited mental capacity, who pleaded guilty, the individuals whose stories are told in the report were convicted after jury trials and were sentenced to long prison terms. They successfully challenged their convictions, using DNA tests on existing evidence. They had served, on average, seven years in prison.

By highlighting the importance and utility of DNA evidence, this report presents challenges to the scientific and justice communities. Among the tasks ahead are the following: maintaining the highest standards for the collection and preservation of DNA evidence; ensuring that the DNA testing methodology meets rigorous scientific criteria for reliability and accuracy; and ensuring proficiency and credibility of forensic scientists so that their results and testimony are of the highest caliber and are capable of withstanding exacting scrutiny.

Meeting these scientific challenges requires continued support for research that contributes to the advancement of the forensic sciences. The research agenda must also enable criminal justice practitioners to understand and to make appropriate use of the rapidly advancing and increasingly available technology.

The National Institute of Justice (NIJ) commissioned this study to encourage discussion of the challenges to the scientific and justice communities presented by DNA evidence. The commentaries presented here - authored by prominent experts from a variety of disciplines - and the cases documented in the pages that follow, are testimony to the power and potential of DNA evidence. We hope that these commentaries and the NIJ report spur a broader debate about the value of DNA technology and the role of science in the criminal justice system's search for truth.