By identifying distinctive patterns in genetic material, new DNA typing tests can determine with unprecedented specificity whether a given individual could have been the source of a biological specimen. The results of DNA typing tests have already been admitted as evidence in a number of criminal cases, although only one of these cases has reached the appellate level. Because it is thought to offer significant advantages over traditional genetic identification tests, DNA typing is likely to be used in forensic analysis and offered as evidence in criminal trials with increasing frequency. Although the legal community's reaction to the new tests has been enthusiastic, some officials warn against becoming mesmerized with DNA's potential and slipping into a counterproductive rush to move the technology from the laboratory to the courtroom. Key issues associated with the reliability of DNA typing evidence concern admissibility and the Frye rule and scientific acceptance of the theory and procedures underlying DNA analysis. There are three general factors to consider in determining the probative value of DNA typing evidence: probability of a coincidental match or likelihood that two unrelated individuals will have the same DNA type; possibility of an erroneous call by a laboratory analyst; and possibility of an artifactual result due to laboratory error or sample contamination. Although DNA typing clearly has potential, it is unclear whether the new tests meet the standard for admissibility under Frye. 278 references.