Opinion ID: 1160857
Heading Depth: 1
Heading Rank: 6

Heading: Further Kelly Hearing in the Superior Court

Text: By stipulation and order, all testimony and exhibits introduced at the preliminary examination were made part of the trial record for purposes of considering the admissibility of DNA evidence at trial. Meanwhile, in Axell, supra, 235 Cal.App.3d 836, 1 Cal.Rptr.2d 411, a published California appellate decision for the first time upheld trial court rulings admitting RFLP analysis of DNA samples as evidence of the identity of the perpetrator of a crime. (See post, 88 Cal.Rptr.2d at p. 51, 981 P.2d at p. 973.) After the Axell decision became final, the present trial court ruled that Axell had settled the general scientific acceptance of such analysis, but that the prosecution would still have to establish that correct scientific procedures were used in the present case. Moreover, the defense would be permitted to show changes in the views of the scientific community after the Axell findings. [23] To show that correct scientific procedures had been used, the prosecution introduced testimony of criminalist Keister and Dr. Kovacs, both of whom had also testified at the preliminary examination. To show post- Axell changes in scientific views, the defense called two population geneticists, Drs. Laurence Mueller and William Shields. Dr. Mueller, an ecologist and population geneticist, was an associate professor in the Department of Ecology and Evolutionary Biology at the University of California, Irvine. He worked primarily with populations of fruit flies. In his opinion there was no consensus in the scientific community in support of the forensic RFLP techniques used in this case. He testified that the variations in probability estimates obtained using different Hispanic databases (i.e., those of the OCSD and FBI) (see post, 88 Cal.Rptr.2d at p. 48, 981 P.2d at p. 971) reflected population substructuring that made it incorrect to apply the unmodified product rule to the OCSD database. In Mueller's opinion there was no existing database that could properly be used in conjunction with the product rule to determine a correct probability estimate in defendant's case. He criticized the OCSD database as failing to reflect ethnic subgroups that he believed account for substructuring. In his opinion, selecting a database from the geographic region where the crime occurred and the potential perpetrators reside (e.g., using the OCSD crime laboratory's Hispanic database in this case) was less important than developing separate databases from the separate ancestral populations that live in places like Cuba, Mexico, Spain and Central America, in order to reflect the genetic background of the particular defendant. To his mind, the relevant comparison was not between the DNA profiles of the matched samples and those of persons residing in the area where the crime occurred (i.e., the OCSD crime laboratory's databases), but between the ethnicity of the person involved and persons in ethnicity-defined databases. (But cf. fn. 27, post at p. 49, 981 P.2d at p. 972.) Mueller testified that, as an alternative to the unmodified product rule, he would use the 1/database method of calculating a probability estimate, together with a correction for the rate at which the laboratory makes false positives, because he preferred a rule that did not make the assumptions of Hardy-Weinberg and linkage equilibrium. Under that method (also known as the counting method), Mueller would use a fraction equalling 1/ the number of samples in the database as the probability estimate for the four-probe DNA profile. In other words, Mueller would simply count how many people in the database matched the four-banded pattern. Assuming no match in the database, the probability would be reported as a fraction equalling 1/the number of samples in the database (modified by a confidence interval). In the present case, this would result in a probability estimate of approximately 1/250, since there were approximately 250 samples in the OCSD crime laboratory's Hispanic database. Dr. William Shields, a professor at the State University of New York College of Environmental Science and Forestry, who had done work in population and conservation genetics, also testified for the defense. Shields's work mostly involved the study of small mammals; he had never worked directly with RFLP analysis of human DNA samples. Shields believed that representative samples, not random samples, were necessary for a valid database. He suggested that obtaining representative samples would involve sampling not only the frequency variance among subpopulations, but also the frequency with which the subpopulations occur in the total population. In his opinion, use of the 1/database or counting method was the most reliable if you're going to put a number in at all. On February 10, 1992, the trial court concluded that correct scientific procedures had been used and that there had been no material change in scientific acceptance of statistical evidence generated by the unmodified product rule since the filing of the Axell decision. Accordingly, the court ruled that the incriminating DNA evidence produced by the OCSD's crime laboratory met the requirements for admissibility set forth in Kelly, supra, 17 Cal.3d 24, 130 Cal.Rptr. 144, 549 P.2d 1240.