A San Francisco man has been convicted for the second time of a 30-year-old rape and murder of a Potrero Hill woman based on “cold hit” DNA evidence, District Attorney George Gascon announced today.
John Davis, 49, has been found guilty by a jury of first-degree murder committed during the course of a rape and burglary for the Dec. 4, 1985 murder of 28-year-old Barbara Martz, prosecutors said today.
Davis was identified as the suspect in Martz’ murder in 2002 after samples of semen taken from her body were used to develop a DNA profile. He was serving a prison sentence at Pelican Bay State Prison at the time for a 1993 San Francisco robbery.
Prosecutors at the time said Davis had stabbed Martz to death with a butcher knife after she arrived home to find him burglarizing her home.
He was tried and convicted of the murder in 2007, but that conviction was later overturned on appeal in 2013 due to juror misconduct, prosecutors said today.
Jurors convicted him again more than eight years later after only a day of deliberation, Gascon said today.
“If you commit a heinous crime in San Francisco we will do everything ethically possible to bring you to justice,” Gascon said in a statement today. “Justice may be delayed but it won’t be denied.”
Bay City News