DNA testing has had widespread repercussions because of the nature of the DNA forensic technique and the historical moment at which DNA entered the courtroom. DNA's origins in the world of science meant that from the beginning of its discovery, scientists whose DNA work was far removed from the courtroom showed an interest in issues regarding the forensic application of DNA. Further, DNA science emerged at a time when there was heated debate about the use of "junk science" to attempt to prove causation in court, thus pressing the U.S. Supreme Court to adopt a new relevancy and reliability test for the admissibility of scientific proof. The Court's entrance into the debate on science led to a heightening of judicial attention to DNA profiling. Under such court scrutiny, DNA profiling was placed on a more secure footing because of additional scientific input. The technical standards for DNA testing were strengthened, the databases used to generate probabilities of matching became larger and more representative, and laboratory performance was improved. Stringent court analysis of the process by which DNA profiles are developed has led DNA laboratories to develop, implement, and monitor quality assurance and control measures defined and approved through accreditation. The quality of laboratory performance is a crucial issue in any trial in which DNA evidence is involved. The quality assurance guidelines that have professionalized DNA forensic laboratories have had a spillover effect in upgrading the quality of forensic services provided by other crime laboratories. This paper concludes with a discussion of issues involved in matches between crime-scene DNA profiles and the DNA profile of the defendant. DNA matching is then compared with matches in other forensic fields, namely, handwriting analysis and fingerprints. Policy implications for the future are discussed. Question-and-answer session and 9 notes