DNA on Gum Solves 1978 Bay Area Cold Case, Killer Sentenced to Life
Mark Stanley Personette, 80, convicted for the murder of 15-year-old Marissa Harvey, with DNA evidence from gum found on the victim's clothing proving crucial.
An 80-year-old Colorado man has been sentenced to life in prison for the 1978 murder of 15-year-old Marissa Rolf Harvey, a cold case that was ultimately solved by DNA evidence recovered from a piece of gum found on the victim's clothing. Mark Stanley Personette was convicted late last year for the crime that occurred after Harvey disappeared on March 27, 1978, while horseback riding in San Francisco's Golden Gate Park.
Harvey, who was visiting her sister in the Bay Area from New York City, never returned home. Her body was discovered by surfers in Sutro Heights Park. Authorities determined she had been sexually assaulted and strangled.
Investigators reopened the case in October 2020, employing advanced DNA testing and investigative genealogy. A male DNA profile was identified on the victim's sweater and jeans, as well as on a piece of gum discovered stuck to her back. This evidence was instrumental in linking Personette to the crime.
FBI investigators located Personette in Denver, Colorado. Evidence found while he was discarding trash in a Walmart parking lot, over 15 miles from his residence, matched the DNA found at the crime scene. According to District Attorney Brooke Jenkins, warrants revealed that Personette had been separating his personal hygiene items from other trash. Inside his home, investigators also found a map of San Francisco and California license plates, despite his denial of ever being in the city.
During the trial, another victim testified that Personette had raped her in 1979, when she was 16, in a wooded area in New Jersey. Prosecutors highlighted the significance of the conviction, with Assistant District Attorney Heather Trevisan stating, "This sentence reflects the extraordinary cruelty of Mark Personette’s conduct and the harm he caused. He will spend the rest of his life facing the consequence of taking hers."
District Attorney Brooke Jenkins commented on the resolution: "After almost 50 years, Mr. Personette is finally being held accountable for his heinous crimes against Marissa and will spend the rest of his life in prison. While nothing can bring Marissa back to her family, today’s sentence hopefully leaves her family with a sense that justice was done for all that they have endured."