People v. Turner

Supreme Court of California · 2020 · Evidence

10 Cal. 5th 786 (2020)

Updated August 22, 2026

EvidenceDNA evidenceExpert testimonyHearsayThird-party culpabilitycold hitDNA database searchrandom match probability

Facts

Defendant was linked to multiple murders after his DNA profile matched DNA recovered from the victims, including matches found through database comparison. At trial, prosecution experts testified to random match probabilities derived from the product rule, and defendant argued those statistics were improper in a cold hit case. On the fetal murder count, a pathologist who had not performed the autopsy testified from the autopsy report that the fetus weighed 825 grams and had a gestational age of 27 to 28 weeks, and used those facts to opine that the fetus was viable. Defendant also sought to introduce evidence that police had compared a partial shoe print from one scene to another person's shoe, but the print was too poor in quality to identify any source.

Issue

Whether, in a cold hit DNA case, product-rule random match probability evidence is admissible without a Kelly hearing and sufficient to show the rarity of the DNA profile; whether an expert may relay case-specific hearsay from an autopsy report to prove fetal viability; and whether exclusion of weak third-party culpability evidence was error.

Rule

In a cold hit case, the statistic generated by the product rule is admissible without a Kelly hearing because the competing statistical approaches answer different questions and the dispute is one of relevance, not scientific reliability. The product-rule statistic remains relevant because it expresses the rarity of the matching profile in the population, even if the defendant was identified through a database search. Under Sanchez, an expert may rely on hearsay in forming an opinion but may not relate case-specific hearsay as true unless those facts are independently proven by competent evidence or fall within a hearsay exception. Third-party culpability evidence is admissible only if direct or circumstantial evidence links the third party to the actual perpetration of the crime.

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One of 10 multiple-choice questions for this case. Pick an answer to see why.

In Phoenix, investigators uploaded DNA from an unsolved assault to a state offender database and identified Marcus Hale after a database match. At trial, a forensic analyst testified that the matching 13-locus profile would occur in approximately 1 out of 4 quintillion unrelated people, using the product rule. The defense demands a Kelly hearing, arguing that because Marcus was found through a database search, the statistic is scientifically improper.

How should the court rule on the objection?

Explanation. The majority held that in a cold-hit case, use of the product-rule statistic does not require a Kelly hearing. The accepted method still accurately expresses the rarity of the profile; the debate is over which statistic is most probative after a database search, which is a relevance issue rather than a scientific-reliability issue.