United States v. Williams
979 F. Supp. 2d 1099
D. Haw.2013Background
- Defendant Naeem Williams is charged with killing five-year-old Talia Williams; the government will offer PCR STR DNA expert testimony linking blood found in the residence to Talia.
- FBI testing used Applied Biosystems PCR STR kits to generate 13-locus STR profiles; Onorato concluded, to a reasonable degree of scientific certainty, that several samples came from Talia.
- Defendant moved to exclude the DNA identification testimony under Daubert, arguing the Onorato report failed to account for primer binding-site mutations and allelic dropout that can differ between kit manufacturers (Applied Biosystems vs. Promega).
- The court previously denied most aspects of the motion, leaving the single remaining issue: whether failure to account for primer-site mutations (null alleles/allelic dropout) renders the DNA identification inadmissible.
- Parties briefed People v. Pizarro (raising allelic-dropout concerns); Pizarro was later depublished and the parties submitted supplemental briefs and declarations from an FBI examiner explaining lab practices and the rarity/management of null alleles.
- The court concluded PCR STR analysis is well-accepted, null-allele concerns go to weight not admissibility, and denied the renewed motion to exclude the DNA/serology expert testimony on the remaining issue.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Admissibility under Daubert of PCR STR DNA identification when primer binding-site mutations/allelic dropout possible | DNA testing using validated FBI Applied Biosystems kits is reliable and accepted; standard procedures manage null alleles | Onorato failed to account for primer-site mutations/allelic dropout; differing primers between manufacturers can produce false matches | Denied — PCR STR testing is generally reliable; null-allele concerns go to weight and cross-examination, not exclusion |
Key Cases Cited
- Daubert v. Merrell Dow Pharm., 509 U.S. 579 (1993) (federal standard for admissibility of expert scientific testimony)
- People v. Kelly, 17 Cal.3d 24 (1976) (California test for admission of scientific evidence)
- People v. Pizarro, 158 Cal.Rptr.3d 55 (2013) (court of appeal discussion of allelic dropout; later depublished)