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Cigarette DNA and Genetic Genealogy Lead to Conviction in 1982 Killing of California Teen

A discarded cigarette tied by genetic genealogy to a 2003 DNA profile provided the link that jurors needed.

Overview

  • Jurors found James Oliver Unick guilty on Feb. 13 with a special-circumstance finding, triggering a life-without-parole sentence at an April 23 hearing.
  • In 2003, investigators built a DNA profile from sperm on Sarah Geer’s clothing, but it matched no law-enforcement databases at the time.
  • Starting in 2021, investigators used familial genetic genealogy to narrow the source to one of four brothers related to the DNA profile.
  • FBI surveillance collected Unick’s discarded cigarette, and testing matched his DNA to the 2003 profile and to DNA on the victim’s clothing.
  • Unick was arrested in July 2024 and testified at trial that he had consensual sex with the 13-year-old, a claim the jury rejected after about two hours of deliberation.