Opinion ID: 2262050
Heading Depth: 2
Heading Rank: 6

Heading: Identifying the Consensus.

Text: We leave to the trial judge the initial determination as to whether the requisite consensus now exists for a conservative statement of the probability of a coincidental match and, if so, what the probability is in the present case. We do so, in part, because this issue was not focused upon by the court and counsel during the Frye hearing. [24] Although it appears improbable, in light of recent events, that no conservative consensus can be found, it would be unfair to Porter for the appellate court to proclaim ex cathedra the precise (and minimal) probability of a coincidental match without a crossing of swords on the issue in the court below. The information presently before the court suggests, however, that the odds against a match being the result of a coincidence are extremely high even if one uses the most conservative reasonable calculation. In Barney, supra, the court admitted evidence that the blood of one of the defendants and the evidentiary sample in his case shared an unusual blood type found in only 1.2 persons out of 1000 in the Black population. 8 Cal.App. 4th at 828, 10 Cal. Rptr.2d at 748. In holding that the trial judge had committed error (but harmless error) when he admitted evidence that the probability of a coincidental DNA match was one in two hundred million, the court recognized the irony in finding a frequency estimate of 1.2 in 1,000 to be significant while excluding DNA evidence which would have to be in error by five or six orders of magnitude  a degree of error not even claimed by Lewontin and Hartl  to approach a reduced equivalence. This does not, however, undermine our finding of no general acceptance, but rather underscores the need to find a low threshold of agreed statistical significance for DNA evidence. Id. at 826 n. 6, 10 Cal.Rptr.2d at 748 n. 6. [25] In Bridgett, Judge Richter rejected the government's proffered probability evidence, agreeing with Judge Kennedy that the prosecution had failed to demonstrate general acceptance of the FBI's methodology. The judge nevertheless held that a more conservative estimate based on the NRC REPORT'S modified ceiling principle was admissible. Having noted the standing and impartiality of the authors of that study, [26] the judge wrote as follows: This present lack of consensus should not, however, exclude probative DNA evidence if the deficiencies can be corrected through the use of conservative estimates. Indeed, the NAS report assumed that certain populations may be stratified or substructured and that such a phenomenon would not be evident in the frequencies employed by the FBI since the Hardy-Weinberg rule is a poor test to detect disequilibrium. The report concluded, however, that such deficiencies should not function to completely exclude DNA evidence from the courtroom, but may be corrected by ensuring that the probability estimates of a coincidental match between the evidentiary and known samples are appropriately conservative. The report formulated a methodology, the ceiling principle, which calculates the chance of a random match and incorporates the criticisms leveled by opponents of the FBI's methodology. Since the ceiling principle may not be employed until the proper population sampling is computed, the committee has formulated a modified ceiling principle: In effect, a more conservative version of the conservative ceiling principle. The modified ceiling principle may be employed at present since the frequencies are taken from existing databases. This modified formula requires that the largest frequency from the current databases be used for the defendant's allele frequencies. Once this frequency has been determined, one calculates the 95% upper confidence limit, or applies a frequency of 10%, whichever is larger. The committee recommends the use of the 10% frequency floor to account for the unsampled populations' allele frequencies. This Court finds this formula appropriate under Frye for determining the probability estimates to be applied to a match declaration. 120 Daily Wash.L.Rptr. at 1704 (footnotes and citations to NRC REPORT omitted). No appeal from the decision in Bridgett is before us, and we do not at this point rule definitively on Judge Richter's analysis and conclusion. On remand, the court and counsel should address the holding in Bridgett and its potential applicability in this case. [27]