ORDER DENYING DEFENDANTS RENEWED MOTION TO EXCLUDE EXPERT TESTIMONY CONCERNING THE IDENTIFICATION OF BIOLOGICAL MATERIAL [DNA AND SEROLOGY], AND REQUEST FOR DISCOVERY, DOC. NO. 2043, ON REMAINING ISSUE
I. INTRODUCTION
Defendant Naeem Williams (“Defendant”) is accused of, among other things, unlawfully killing five-year-old Talia Williams (“Talia”) in violation of 18 U.S.C. §§ 2, 7(3), and 1111(a) & (b). At the upcoming trial, the government plans to present expert testimony that, to a reasonable degree of scientific certainty, several blood samples found in Defendant’s residence where he and Talia lived are from Talia. This conclusion is based on the results of PCR STR DNA testing, which found that a DNA sample from Talia matched the blood samples at each of the thirteen STR loci tested.
Defendant’s May 28, 2013 Renewed Motion to Exclude Expert Testimony Concerning the Identification of Biological Material [DNA and Serology] (“Motion to Exclude Expert Testimony”), Doc. No. 2043-1, raises several arguments that this PCR STR DNA methodology runs afoul of Daubert v. Merrell Dow Pharm., Inc.,
II. ISSUE PRESENTED
The Onorato Report outlines that a method of testing known as PCR STR DNA testing was employed to determine the source of DNA from samples collected from Defendant’s and Talia’s residence.
Defendant initially argued that the Onorato Report failed to properly take into account the possibility of primer binding site mutations in performing PCR STR
In opposition, the government asserted that the FBI uses Applied Biosystems kits for all of its PCR STR DNA typing, Doc. No. 2068-1, LaSalle Decl. at 17, such that there is no possibility of getting differing results based on a change in the kit used. As Heather LaSalle, FBI Forensic Examiner for the Nuclear DNA Unit, explains, “[a] good analogy for this scenario is that if Applied Biosystems PCR STR DNA kits are like apples and Promega PCR STR DNA kits are like oranges [then] for this case the FBI lab only compared apples to apples.” Id.
In reply, Defendant asserted, in a one-sentence argument, that the government’s explanation lacks merit due to People v. Pizarro,
Because the parties did not address Pizarro in any meaningful way, the court required supplemental briefing addressing: (1) whether Pizarro’s concerns regarding allelic drop-out are viable and applicable in this action, and (2) if Pizarro’s concerns do apply to this action, how such concerns figure into the Daubert analysis. Doc. No. 2135. The government submitted a Supplemental Opposition on September 23, 2013. Doc. No. 2178. In the meantime, Pizarro was depublished on September 18, 2013. On October 11, 2013, the court provided the parties a copy of the letter requesting depublication, which is a public record. Doc. No. 2201. Defendant submitted a Supplemental Reply on October 14,2013. Doc. No. 2202.
III. DISCUSSION
In Pizarro, the defendant challenged the prosecution’s evidence that PCR STR DNA testing established that the defendant’s DNA matched all thirteen loci of a sample found on a rape and murder victim, raising many of the arguments Defendant raises in this action. See
Despite affirming the trial court and recognizing that it was not a scientific body, Pizarro nonetheless took the opportunity to express its opinion that “allelic dropout has the potential to falsely incriminate an innocent defendant.” Id. Pizarro explained that the issue of allelic dropout is not an issue when the same primers are used and the two samples ultimately come from the same person — even if allelic dropout occurs, both samples will display this phenomena and a match will occur because the DNA is the same. Id. Where the two samples at issue come from different people, however, Pizarro expressed concern that allelic dropout in one sample may lead to a false match that falsely incriminates an innocent defendant. Id. at 101. For example, if the perpetrator is a heterozygous 14,19 at a particular allele and the 19 is a mutant allele which drops out, the genotype will appear as a homozygous 14, 14. Id. If the defendant is a homozygous 14, 14, however, he will be considered a match at this allele. Although Pizarro recognized that “[w]e have not found reference to this scenario in the literature,” it asserted that “[i]f our conclusions are accurate, the widely held idea that allelic dropout cannot cause false results in a criminal case as long as the same primers/kit are used on both the defendant’s and the perpetrator’s DNA samples is a very serious falsehood based on the improper assumption that the defendant is guilty.” Id. Pizarro therefore suggested the scientific community consider null allele recovery where the analyst observes a homozygous genotype that raises the suspicion that a second allele has dropped out. Id. at 104-05.
For several reasons, the court rejects that Pizarro supports Defendant’s argument that the PCR STR DNA testing should be excluded pursuant to Daubert. As an initial matter, Pizarro was recently depublished at the California Attorney General’s request. See Doc. No. 2201. The California Attorney General requested that the California Supreme Court depublish Pizarro, a California Court of Appeal, Fifth District opinion, because its discussion regarding null alleles is dicta, is based solely on the court’s own conjecture, and is not supported by scientific evidence. Id. Although the California Supreme Court did not give a reason for depublishing, Pizarro is nonetheless depublished and therefore not precedent under California law and cannot be cited in California courts except in narrow circumstances. See Cal. Ct. R. 8.1115; Farmers Ins. Exchange v. Superior Court,
Second, even if Pizarro’s dicta was pub
Finally, turning to the substance of Pizarro’s concerns, it appears they are based on a misunderstanding regarding the science at issue. The example Pizarro provides of a null allele causing a false match ignores that PCR DNA STR testing involves multiple loci. As LaSalle explains, “[t]he entire 13 locus profile is evaluated by the DNA examiner during interpretation of a DNA profile,” and [t]he potential of having two profiles match completely except for one of two alleles, at one locus (due to a mutation in the primer binding region) is highly improbable.” Doc. No. 2178-1, LaSalle Decl. ¶ 11. In fact,
The-chances of having two profiles that match at twelve loci, but differ at the thirteenth locus due to one allele, is as improbable as two people matching at all thirteen STR loci with only sequence difference in their DNA. Scientifically, these two scenarios are identical, the chances of a null allele difference being the only distinction between two DNA profiles is exceedingly rare.
Id. ¶ 4. Faced with such result, “a DNA examiner would recognize this as an uncommon event and would further examine these profiles in their entirety, examining possible scenarios,” including whether different kits were used, the samples came from close genetic relatives, or that the quality of DNA impacted the results.
In sum, LaSalle exposes significant issues with Pizarro’s assertions that allelic dropout may cause improper identification. And this criticism of Pizarro is only highlighted by the facts that (1) Pizarro recognized it was not a scientific body; (2)
Thus, at most, Defendant’s concerns of allelic dropout go to the weight of the evidence, not its admissibility. The court therefore finds that the PCR STR DNA analysis passes Daubert scrutiny.
IY. CONCLUSION
For these reasons, the- court DENIES Defendant’s Renewed Motion to Exclude Expert Testimony Concerning the Identification of Biological Material [DNA and Serology], Doc. No. 2043, as to the remaining issue.
IT IS SO ORDERED.
Notes
. The court previously outlined the scientific evidence and standard of review in detail in its August 26, 2013 Order, and does not repeat it here. Rather, the court focuses on only those facts necessary to adequately frame the remaining issue.
. Despite California Rule of Court 8.1115, Defendant correctly points out that the Ninth Circuit has on several occasions relied upon unpublished California state opinions. See, e.g., Beeman v. Anthem Prescription Mgmt., LLC,
. For purposes of this action, none of these is a possible scenario in this action — the same kit was used, Talia’s parents were typed and excluded, and the allelic dropout was guarded against by ensuring that peak levels met relevant standards. See Doc. No. 2178-1, LaSalle Decl. ¶ 7.
