An 80-year-old man was convicted Thursday in the decades-old murder of a teenager who was found dead in a San Francisco park.
A jury found Mark Stanley Personette guilty of first-degree murder in the 1978 killing of Marissa Harvey, 15, the San Francisco District Attorney’s office said in a news release.
“At long last, justice has been delivered, and Mr. Personette is being held accountable for this horrific crime,” District Attorney Brooke Jenkins said in a statement.
Personette’s lawyer, Adam Gasner, said in a statement Thursday that he maintains that there was reasonable doubt in the case but respects the jury's verdict.
"The jurors were extremely attentive and were following often dense and complicated forensic evidence," he said.
Harvey had been visiting her sister in San Francisco when she disappeared on March 27, 1978, the prosecutor's office said. She had gone to Golden Gate Park to go horseback riding and never returned.
Surfers found Harvey the next day in the underbrush of a nearby park. An autopsy determined she had been sexually assaulted and strangled, according to the release.
Personette was identified in 2021 through investigative genealogy, a forensic technique that combines DNA evidence collected from crime scenes with information gathered from public and private genealogy databases.
Authorities identified Personette through a comparison of DNA gathered from Harvey’s body and genetic material collected from what the prosecutor’s office described as personal hygiene products that Personette threw out in a Walmart parking lot outside Denver, where he lived at the time.
Personette denied having been in San Francisco, according to the release. Gasner said that multiple DNA profiles were found at the crime scene.
Personette is scheduled to be sentenced Dec. 17 and faces a maximum of life in prison.
