SAN FRANCISCO—On November 15, the San Francisco District Attorney’s Office announced that a conviction was secured against Mark Personette, 80, after a trial by jury for a 1978 cold case murder. He was convicted of first-degree murder.
According to testimony and other evidence presented at trial, on March 27, 1978, the 15-year-old victim Marissa Harvey, who was visiting her sister in San Francisco, went to Golden Gate Park to ride a horse. She never returned to her sister’s home. The following day, her body was discovered in the underbrush of Sutro Heights Park by several surfers who were walking through the region.
At the crime scene, investigators found a leaf with the victim’s blood and her earring, showing that she was attacked there. Her cause of death was determined at the scene to be strangulation by ligature. An autopsy revealed numerous injuries consistent with a violent attack and sexual assault.
DNA testing in the early 2000s revealed a male DNA profile on the victim’s sweater and jeans, as well as within a piece of dried gum stuck to her back. In 2021, through investigative genealogy, Personette was identified as a potential suspect. FBI investigators surveilled Personette, in Denver, Colorado, and observed him discarding trash in a Walmart parking lot over 15 miles from his house. They collected the trash, which included only personal hygiene items with his DNA.
A search warrant at Personette’s house showed that he was separating his personal hygiene items from his other trash. He also had 1970s maps of San Francisco along with a set of California license plates with a 1979 registration sticker, though he denied to investigators that he had been in San Francisco. A confirmatory DNA test showed that the defendant’s DNA profile was on the victim’s sweater and jeans, and the piece of dried gum.
A prior victim of Personette testified that in 1979, a year and a half after Marissa’s death, he raped her in a wooded area of New Jersey when she was 16 years old.
“This case shows that time cannot thwart justice,” said Assistant District Attorney Heather Trevisan. “I have not seen, in 25 years, more people willing to sacrifice their time and personal comfort to do their duty. I am proud to have prosecuted this case alongside a dedicated team who worked tirelessly to ensure justice was done and that we honored the survivor and the victim’s family who put their faith and trust in us.”
“After nearly half a century, this verdict brought long-overdue justice for 15-year-old Marissa Harvey,” said Assistant District Attorney Katherine Wells. “We are deeply grateful to her unwavering family, the courageous survivor who testified about Personette’s assault on her, and SFPD’s tireless efforts through the decades to bring Mark Personette to justice. Thank you to the jury who conscientiously considered the evidence in this harrowing case and proved that time and distance will not shield those who commit heinous acts in San Francisco.”
Personette is currently in custody. He is facing seven years to life in prison. Sentencing is scheduled for December 17, 2025.
