A state Court of Appeal panel has denied a San Francisco man's bid to overturn his conviction for a 1985 rape and murder -- a case police and prosecutors brought 17 years after the crime based on a "cold hit" in a DNA database.
In an unpublished opinion made public Thursday, a three-judge panel of the state Court of Appeal's 1st District rejected arguments by lawyers for John Davis -- convicted in January 2016 of robbing, raping and fatally stabbing 28-year-old photographer Barbara Martz in her Potrero Hill home -- that the San Francisco Superior Court judge in his 2016 trial erred in allowing the jury to hear details of an unrelated robbery.
In that episode, which occurred more than two years after Martz's killing, Davis brandished a hatchet as he confronted a Potrero Hill couple in their home. At one point, Davis swung the hatchet to smash a teapot one of his victims was holding. He ultimately robbed the couple of $200 to $300 and fled without physically harming them.
One of the victims -- the man holding the teapot -- testified that he had not really been scared during the confrontation.
“The man was not that menacing," he said. "He seemed high . . . I suppose I should have been scared with the hatchet. I didn’t believe he was capable of actually hitting me with that.”
Davis' appellate lawyers argued that admitting the testimony about the hatchet incident and allowing the jury to consider it during deliberations violated his rights to due process and a fair trial.
In rejecting the appeal, the three-judge panel declared that in light of "the exceptionally strong evidence of [Davis'] guilt," the relatively brief testimony about the hatchet incident did not prejudice the jury's verdict.
The principal evidence against Davis was his DNA, found in sperm recovered from Martz's body after she was found dead Dec. 4, 1985, and not identified as his until 2002.
Davis was tied to the killing after San Francisco police investigators chose the unsolved murder as one to pursue using new laboratory facilities. A DNA profile developed from the recovered sperm was found to match that of Davis, who was incarcerated in state prison at the time the investigation was reopened.
Davis told investigators he had never met Martz and denied having raped or killed her. In his first trial, in 2007, Davis' lawyer, Gabriel Bassan, attacked the reliability of the genetic evidence implicating his client.
The jury in that trial found Davis guilty of murder, but a state appeals court threw out the verdict because of juror misconduct. The San Francisco District Attorney's Office challenged the appellate court ruling and lost, leading to Davis's 2016 trial.
In that proceeding, Bassan conceded at the outset that the DNA recovered from Martz's body came from Davis. He explained that his client, who was 18 at the time of the killing, had consensual sex with Martz before the murder. In making his case, Bassan suggested an alternate suspect: Martz's boyfriend, who discovered her body and made the initial report to police.
The appeals court, like the jury in the second trial, rejected Bassan's assertions. The panel's ruling called the defense's claim that Martz and Davis had consensual sex "incredible," noting there was no evidence "from any source remotely suggesting a possible consensual sexual encounter."
The opinion called the evidence produced to implicate Martz's boyfriend "extremely weak."