Opinion ID: 1160857
Heading Depth: 1
Heading Rank: 7

Heading: DNA Evidence Introduced at Trial

Text: Criminalist Keister testified he prepared four autorads in this case, each depicting VNTR fragments at a different DNA locus. The loci examined by the OCSD laboratory were D1S7, D2S44, D4S139, and D10S28, situated on chromosomes 1, 2, 4, and 10 respectively. (See Venegas, supra, 18 Cal.4th at p. 68, fn. 24, 74 Cal.Rptr.2d 262, 954 P.2d 525 [explaining locus numbering system].) [24] Keister found that the size differences between the eight bands of the known sample and those of the questioned sample on each of the four loci were 1.01 percent or less, well within the OCSD crime laboratory's match criterion of 3.4 percent. Keister then determined the statistical probability that alleles numerically indistinguishable from the matched bands would appear in the databases of DNA collected from representative populations. The OCSD had created those databases by obtaining blood samples that the Red Cross collected from its Orange County blood bank and identified as Hispanic, Caucasian, Black, or Asian. [25] The OCSD then performed RFLP analysis on each sample, calculating the base-pair sizes of the bands at each of the four DNA loci at which comparisons were to be made. For each locus, there was constructed a fixed-bin table, initially consisting of 31 bins, or ranges of sizes, based on the 31 fragments of known length in the marker lanes customarily included in the autorads. The database bands were sorted into the bins by base-pair size. Any bin that contained less than five bands was rebinned by combining it with its neighbors until each bin contained a minimum of five bands. All bands in each bin were deemed to have a common frequency, calculated from the ratio of the number of bands in the bin to the number of bands in the entire table. (See Venegas, supra, 18 Cal.4th at pp. 64-65, 74 Cal.Rptr.2d 262, 954 P.2d 525.) Keister testified his initial comparison of the DNA profile of defendant's blood sample was with the OCSD Hispanic database of about 250 individuals, because the frequency in the database from the suspect's ethnic group will generally be the most frequent number. As noted, defendant's sample had produced eight bands, two at each locus. Keister determined the frequency of each individual band in the Hispanic database from the fixed-bin tables, then used the unmodified product rule to ascertain the statistical probability of finding all combined eight bands in any one person in the population represented by that database. [26] In that manner, he calculated the probabilities of finding defendant's DNA profile in the populations underlying four Orange County databases as follows: (1) Hispanic: 1 in 189 million; (2) Caucasian: 1 in 38 million; (3) Black: 1 in 807 million; (4) Vietnamese: 1 in 177 million. Keister also calculated the probabilities of finding defendant's 8 bands in individuals from 4 populations underlying databases published by the FBI, as follows: (1) Southwest Hispanic (Texas): 1 in 55 million; (2) Southeast Hispanic (Florida): 1 in 2.3 billion; (3) U.S. Black: 1 in 2.4 billion; and (4) U.S. Caucasian: 1 in 3 billion. [27] Keister also made a calculation using floating bins, instead of fixed bins, to measure the probability of finding defendant's profile in the Orange County Hispanic database. [28] He sorted all the database fragments, in the order of their numerical size, into a table for each of the four DNA loci. At the two points on each table where the sizes of defendant's bands would place them, Keister superimposed a floating bin, ranging from 3.4 percent more to 3.4 percent less than the size of defendant's band, and counted the number of fragments within that bin. The frequency of the band was calculated by dividing the number of fragments in the bin by the total number of fragments in the table. Applying the product rule to those results, Keister calculated the frequency of defendant's eight-band pattern in the database at 1 in 6.7 billion. He explained that the size of the floating binplus or minus 3.4 percentwas based on the OCSD laboratory's match criteria. He said the fixed bins are generally wider than the floating bins, use of which results in a less frequent number. Dr. Bruce Kovacs, who, like Keister, had testified in the preliminary examination, testified as a DNA witness at trial. As noted, Kovacs was a professor of medicine at the University of Southern California Medical School and did research in medical genetics, using RFLP analysis to study human gene mutations. ( Ante, 88 Cal. Rptr.2d at p. 46, 981 P.2d at p. 969.) When asked his opinion on the significance of the variations between the population frequencies calculated from the various OCSD and FBI databases, he testified, They [the denominators] are astronomically large numbers. The significance of whether something is 1 in 55 million or 1 in 110 million versus 1 in 4 billion is something that I can't really get my hands on in a real concrete way to distinguish that difference. It's a very, very, very rare event. Dr. Kovacs also expressed his view that Daniel Lewontin's and Richard Hartl's published criticism of the unmodified product rulesee Lewontin and Hartl, Population Genetics in Forensic DNA Typing (Dec. 20, 1991) 254 Science 1745-1750 (Lewontin and Hartl article) was based on a theoretical model that was not demonstrated by actual data. The DNA witnesses called by the defense at trial were Laurence Mueller and William Shields, each of whom had testified at the further Kelly hearing in the trial court ( ante, 88 Cal.Rptr.2d at pp. 47-48, 981 P.2d at pp. 970-971), and Seymour Geisser, director of the School of Statistics at the University of Minnesota. Mueller, the University of California, Irvine biology professor who also testified in Venegas (see 18 Cal.4th at pp. 90-91, 74 Cal.Rptr.2d 262, 954 P.2d 525), repeated the criticisms to which he had testified at the reopened Kelly hearing, i.e., that the unmodified product rule failed to reflect the distorting effects of population substructuring. ( Ante, 88 Cal.Rptr.2d at pp. 47-48, 981 P.2d at pp. 970-971.) He testified he would have used the more conservative /database or counting method for generating a probability frequency in this case. Shields, the State University of New York College of Environmental Science and Forestry professor who has done work in population and conservation genetics with small mammals, likewise repeated much of his testimony given at the reopened Kelly hearing. ( Ante, at p. 48, 981 P.2d at p. 971.) Seymour Geisser, a professor at the School of Statistics at the University of Minnesota, is a biostatistician, not a population geneticist. In his opinion, the unmodified product rule should not have been used to calculate a probability estimate from the OCSD crime laboratory's database because statistical independence (i.e., Hardy-Weinberg equilibrium and linkage equilibrium) were suspect in the database. He thought at least two and possibly three out of the four probes used in this case were not in Hardy-Weinberg equilibrium, and that use of the 1/database or counting method of calculating a probability frequency would have been more appropriate. The prosecution then presented two rebuttal DNA witnesses: Drs. David Goldman and Kenneth Kidd. Dr. Goldman testified his laboratory at the National Institute of Health employed the unmodified product rule in its genetic research into neuropsychiatric disorders, particularly alcoholism. He was aware of the debate among some scientists over whether the rule should be used; it centered on whether Hardy-Weinberg equilibrium and linkage equilibrium are met before the rule is applied in frequency determinations. He was aware of the research indicating there is independence of alleles, i.e., that the necessary assumptions regarding equilibrium support use of the product rule to calculate frequency determinations. He was also aware of the OCSD crime laboratory's database and believed it was sufficiently large to properly apply the product rule in its frequency determinations. Dr. Kidd was a professor of human genetics, psychiatry and biology at Yale University, a director of the human genome mapping project, and director of the Yale University DNA research laboratory. He acknowledged the debate regarding probability estimates. His opinion was that any greater precision was impossible; the product rule could be applied because the frequency determination derived from it was still as accurate as any determination could be. Although the greater the database the greater the certainty of the estimate, any difference in estimates over one in a million was pragmatically meaningless. Finally, empirical data proved there was no significant substructuring; the larger the database, the more uniform the distribution of gene size became. Like Kovacs, he was of the view that Lewontin's and Hartl's published article was primarily a hypothesis with no empirical data to support it. [29] The case was submitted to the jury on March 9, 1992, and the verdict finding defendant guilty of the lesser included offense of attempted rape returned on March 11, 1992. On April 29, 1992, defendant filed a notice of motion for new trial. Attached to his points and authorities was an advance copy of the 1992 NRC Report, which had been released on April 14, 1992. A supporting affidavit by Laurence Mueller asserted that the report represented a significant shift in the academic community's views on the product rule, and that there was no longer a consensus on the subject within that community. At the hearing on the motion on May 22, 1992, the defense called Mueller to testify on the significance of the 1992 NRC Report as newly discovered evidence, and the prosecution called Keister in opposition. Mueller testified that applying the modified ceiling method described in the 1992 NRC Report, he calculated the Soto frequency at 1 in 182,000. He used fixed bins and a combination of the following databases: OCSD Hispanic, Caucasian, and Asian; and FBI Texas Hispanic, Florida Hispanic, and Sioux Indian. Keister testified he had recalculated the Soto frequencies using the 1992 NRC Report's modified ceiling method and the OCSD databases and got the following frequencies: Using floating bins: 1 in 5 million. Using fixed bins: 1 in 500,000. Upon conclusion of the testimony, the motion for a new trial was denied, the trial court commenting that the 1992 NRC Report did not undercut the court's obligation to follow Axell, which had endorsed use of the unmodified product rule under the Kelly standard.