People v. Turner
10 Cal.5th 786
| Cal. | 2020Background:
- Chester Dewayne Turner was identified by a 2002 DNA cold-hit and later convicted of murdering 10 women (and one viable fetus) based on DNA matches from preserved sexual-assault evidence; he received the death penalty.
- Prosecution experts matched defendant’s DNA to evidence from each victim at 13 STR loci; LAPD and a private lab reported astronomically small product-rule random-match probabilities (e.g., 1 in 1 quintillion; 1 in 6.725 quintillion).
- Defense testing used Y-STRs (male-line markers) with much weaker discriminatory power; defense emphasized limits on time-since-deposition and possibility of other male contributors in some samples.
- At trial an expert (who did not perform the autopsy) recited case-specific autopsy findings (fetal weight and gestational age) and opined the fetus was viable; no foundational hearsay exception was established for the autopsy report.
- On automatic appeal the Supreme Court affirmed the convictions and death sentence except it reversed the fetal-murder conviction because the expert’s case-specific hearsay about fetal viability was erroneously admitted and prejudicial.
Issues:
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Admissibility of product-rule random-match statistics in a cold-hit (database search) case | Product-rule rarity stats are relevant and admissible to show how rare the matching profile is | Product-rule random-match probability misstates significance after a database trawl; Kelly reliability hearing required | Affirmed Nelson: product-rule statistic is relevant in cold-hit cases; admissibility is a relevance, not Kelly, question; trial court did not err admitting it |
| Sufficiency / weight of DNA evidence about profile rarity | Reported random-match numbers conveyed the profile’s rarity and supported conviction | Jury lacked proper evidence of rarity because database-search context was not adequately addressed | Substantial evidence supports guilt; product-rule statistics (even when phrased as "random match") conveyed rarity and were properly admitted |
| Expert testimony reciting autopsy report (fetal weight/age) on viability | Expert’s reliance on autopsy supported viability finding | Case-specific hearsay and confrontation violations; autopsy facts were not independently proven or admitted under a hearsay exception | Reversed fetal-murder conviction: admission of case-specific hearsay through expert was state-law error and prejudicial to that count; penalty unchanged |
| Exclusion of third-party shoe-print comparison evidence (Washington case) | Exclusion proper because print was too small/poor to link third party and admission would invite hearsay/speculation | Exclusion deprived defendant of evidence pointing to alternate perpetrator | Affirmed exclusion: no direct/circumstantial link to third party and risk of confusion/hearsay justified exclusion |
| Excusal of prospective jurors for cause (death-penalty views) | Prosecution: jurors’ voir dire showed inability or substantial impairment to impose death | Defendant: jurors improperly dismissed despite questionnaire support for death penalty | Affirmed: trial court’s demeanor-based and equivocal answers provided substantial evidence jurors were substantially impaired |
Key Cases Cited
- People v. Nelson, 43 Cal.4th 1242 (Cal. 2008) (product-rule statistics admissible and relevant in cold-hit cases)
- People v. Sanchez, 63 Cal.4th 665 (Cal. 2016) (expert may not relate case‑specific hearsay as true without exception; limits on using hearsay as basis for opinion)
- People v. Venegas, 18 Cal.4th 47 (Cal. 1998) (discussing product rule and modified ceiling approaches)
- People v. Soto, 21 Cal.4th 512 (Cal. 1999) (acceptance of the unmodified product rule to express match significance)
- People v. Kelly, 17 Cal.3d 24 (Cal. 1976) (Kelly/Frye framework for new scientific techniques)
- United States v. Jenkins, 887 A.2d 1013 (D.C. 2005) (analysis of database-search statistical issues and relevance vs. methodology)
- People v. Davis, 7 Cal.4th 797 (Cal. 1994) (on viability requirement and prospective application)