Crime and Safety Report

in by

More than 30 years have passed since photographer Barbara Martz was robbed, raped and knifed to death in her home near 25th and Texas streets.  In late-January a jury convicted a San Francisco man of her rape and murder for the second time.

John Davis, 49, was found guilty of first-degree murder with special circumstances, according to the District Attorney’s Office. Davis was first convicted of Martz’s murder in 2007, but that decision was overturned two years ago because of juror misconduct during deliberations.

This time, the jury considered the evidence for one day before finding Davis guilty of murder during the course of a rape and burglary.

“If you commit a heinous crime in San Francisco we will do everything ethically possible to bring you to justice,” District Attorney George Gascon said in a statement. “Justice may be delayed, but it won’t be denied.”

On December 4, 1985, at approximately 8:30 p.m., Bobby Adams went to his girlfriend’s, Martz, home at 1510 25th Street.  Adams found the front door to the house open and Martz lying dead on the floor inside.  Martz was nude and had been stabbed and cut several times.  The police found a bloodstained knife that’d been taken from Martz’s kitchen on a walkway between her house and the street. 

Davis, 18 years old at the time, lived a block away from Martz, but wasn’t immediately considered a suspect.

San Francisco’s medical examiner’s office took samples of semen from Martz’s body and stored them in a freezer, according to the District Attorney’s Office. In 2002, investigators developed a DNA profile from the samples which were linked to Davis, who was serving time at Pelican Bay State Prison for robbery. A jury found Davis guilty of murder committed in the course of rape and burglary.  Davis was sentenced to life in prison without parole. 

On appeal, Davis contended the judgment against him had to be reversed and a new trial ordered because the trial court excluded scientific material relevant to the prosecution’s DNA evidence, the prosecutor misled the jury during closing argument, and Davis was denied his constitutional right to confront witnesses against him, among other misconduct.  The appeal was granted. 

“Thanks to science and the law we were able to bring justice to this family,” prosecutor Andrew Ganz, an assistant district attorney, said in the press release. “Being able to hold this defendant responsible after so many years is an extremely rewarding experience.”

The case was the first time DNA helped San Francisco police solve a violent crime with no known suspect, police said when Davis was first charged.