Man jailed for 1978 murder after DNA from gum identifies him

Mark Stanley Personette, 80, has been sentenced to life in prison for the 1978 murder of 15-year-old Marissa Harvey in San Francisco. The case matters because DNA evidence and investigative genealogy helped identify and convict him more than four decades after the crime.

Harvey was visiting her sister when she went missing after a trip to Golden Gate Park; her body was found the next day, and prosecutors said she had been sexually assaulted, beaten and strangled. Earlier tests found a male DNA profile on her clothes and on gum stuck to her back, but it was not linked to a named suspect until investigators matched it with DNA recovered from Personette’s discarded rubbish in 2021. A map of San Francisco and old California number plates were also found at his home, while a woman testified that he had raped her in New Jersey in 1979.