The Admissibility of DNA Evidence

01 Jan 1991

In contrast to the widespread acceptance of red blood cell grouping, blood serum protein and enzyme analysis, and HLA typing, the evidentiary status of forensic applications of recombinant-DNA technology is in flux. A proper evidentiary analysis must attend to the fact that there is no single method of DNA typing. As with the more established genetic tests, the probative value of the laboratory findings depends both on the procedure employed and the genetic characteristics that are discerned. This paper describes some of these procedures and the theory that lies behind them, and then considers the developing case law. Given the ongoing debate over the standards and controls that should be used in DNA typing, perhaps the findings of laboratories that have yet to establish a track record on independently administered, blind proficiency tests should be inadmissible, while proof that a laboratory has participated successfully in blind proficiency tests and has applied a similar or more rigorous protocol to the samples at bar should satisfy the threshold test for admissibility. In addition, the performance of the laboratory on the proficiency tests should accompany the results provided to the judge or jury. In this way, the trier of fact will be better positioned to assess the ability of the laboratory, using whatever type of DNA analysis and quality controls it has adopted, to obtain and interpret DNA profiles correctly.