Court Opinion

ID: 9606626
Source: CourtListenerOpinion
Date Created: 2023-08-22 02:51:22.916914+00
Date Added: 2024-06-11T18:02:34.921995
License: Public Domain

Utter, J.
(concurring) — I write to reiterate the concerns articulated in Justice Dore's dissent in State v. Cauthron, 120 Wn.2d 879, 846 P.2d 502 (1993). Namely, until such time as a technique for computing the statistical probabilities is accurate enough to be accepted by a consensus in the relevant scientific community, DNA evidence should not be admitted to inculpate defendants.38 At the very least, only the statistical evidence upon which a consensus of experts would agree, i.e., only the most conservative of statistical probability estimates, should be presented to the jury. I concur in the disposition of this case only because the defendant did not raise issues regarding the general acceptance of DNA forensic evidence or the statistical component of DNA testing. See majority, at 539-40. The latter is the issue on which Justice Dore based his dissent in Cauthron.
Reconsideration denied August 9, 1993.

For a clear and concise description of the problems attending the determination of DNA "matches", see Koehler, DNA Matches and Statistics: Important Questions, Surprising Answers, 76 Judicature 222, 224 (1993). Reported matches may not be "true" matches because laboratories make mistakes, and because even if the defendant is the source of the trace, the defendant may innocently have left the trace before or after the crime was committed. More problematic still is the method used for estimating "random match probability", i.e., the theoretical likelihood that a randomly selected person from the general population (or a large racial or ethnic group) would genetically match the trace evidence as well as the defendant:
An important criticism of DNA frequency statistics is that they fail to take into account the population of interest. The frequency statistics computed by most laboratories compare the defendant to a randomly selected person in some general population (e.g., North American Caucasians). ... [However] the general population may not be a fair genetic representation of the potential source population, the group of people who might reasonably be the source of the recovered trace evidence.
Koehler, at 227.