San Francisco murder case solved after 47 years

A nearly 50-year-old San Francisco cold case has come to a close after a Colorado man was found guilty this week of killing a teenager visiting San Francisco back in 1978, according to the San Francisco District Attorney’s Office.

Fifteen-year-old Marissa Harvey was visiting her sister when she went missing on March 27, 1978, after saying she was going to Golden Gate Park. A day later, Harvey’s body was found at Sutro Heights Park, with signs she had been sexually assaulted. 

Harvey was found to have died of strangulation. 

The San Francisco Police Department’s homicide division responded to the scene, but the case went cold for decades, with no suspect identified. In 2000, new technology allowed law enforcement to pull DNA from Harvey’s clothing and some used chewing gum found on her back.

It took 21 more years before SFPD’s cold case division was able to use that DNA to identify a suspect via investigative genealogy and homed in on Mark Personette. 

In a joint operation with the FBI, law enforcement surveilled Personette in Denver, where he lived, and watched as he discarded trash about 15 miles from his home. They then used that trash to obtain his DNA and found it was a match for the DNA found on Harvey’s clothing and the gum at the scene.

While Personette claimed he had not been in San Francisco at the time, law enforcement also found 1970s maps of the city and a set of California license plates with a 1979 registration sticker. During the trial, another woman testified that Personette had sexually assaulted her a year and a half after Harvey’s murder. 

“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. “I would like to thank the survivor and the victim’s family for never losing hope and remaining steadfast in their commitment to seeing justice done.”

After being found guilty of murder, Personette, now 80, faces seven years to life in prison. He is expected to be sentenced on Dec. 15.