A San Francisco Superior Court jury has returned a verdict of guilty in a 30-year-old murder case in which the suspect was identified by a cold hit in a DNA database.
The jury of 10 men and two women convicted John Davis for the Dec. 4, 1985, murder of photographer Barbara Martz, who was robbed, raped and slashed and stabbed to death in her home near 25th and Texas streets on Potrero Hill. Thursday's conviction on first-degree murder, with special circumstances for a homicide committed during the course of rape and burglary, carries a sentence of life in prison without possibility of parole.
"I hope this verdict finally puts an end to this case," David Martz of Manchester, Massachusetts, the victim's brother, said via text. "My family and Barbara's friends have suffered long enough."
San Francisco police made no progress in solving the crime, which got only passing media attention at the time, for nearly 17 years. In 2002, DNA evidence linked Davis, then in state prison for other offenses, to the crime. At the time of the murder, Davis lived in a Potrero Hill public housing project, about 100 yards from Martz's home.
In reaching the verdict, the jury rejected arguments from defense attorney Gabriel Bassan that evidence in the case provided what he called "a forensic alibi" for Davis.
Bassan conceded at the outset of the two-week trial that the DNA in the case, from semen discovered during an autopsy the day after the killing, came from his client. But its presence, he said, was due to a consensual relationship between Martz, 28, and Davis, who was 18 at the time of the murder.
As proof, Bassan presented a peer-reviewed study carried out by the Denver Police Department and the University of Colorado School of Medicine that sought to determine how quickly sperm deteriorate after sexual intercourse. He contended the study and sperm samples recovered during the autopsy proved that Davis and Martz had sex well before the time of the murder -- possibly days earlier.
Bassan also urged the jury to consider an alternative scenario: that Martz's longtime boyfriend might have stabbed her in a jealous rage. He accused police of failing to have adequately investigated that possibility.
He pointed to testimony that Martz and the boyfriend, Bobby Adams, had experienced difficulties in their relationship. He also called a recently discovered witness, a former neighbor of Martz who, while admitting her memory was shaky about the sequence of events, testified that Adams had come to her home in an agitated state the day of the murder and asked to use her telephone. The jury was not allowed to hear testimony that Adams had taken and passed two polygraph, or "lie detector," examinations.
In closing his case, Assistant District Attorney Andrew Ganz argued the Denver sperm study was not conclusive and there was no evidence that Davis and Martz had any contact before the time of the killing. He pointed to the fact Davis had repeatedly denied recognizing her when a police homicide inspector showed him pictures of Martz in 2002.
Ganz also argued Davis had incriminated himself when he made only conditional denials when the inspector, Jim Spillane, asked whether he had burglarized Martz's home or committed a rape. Davis did not testify during the trial.
The jury deliberated for about eight hours before returning with its decision.
"The entire case boiled down to the DNA evidence," said the jury foreman, Tony Smith. "The defense's position -- that between the studies they introduced and what was found in the autopsy proved that the relationship between the defendant and victim took place at a previous time than the murder -- it was not believable to us."
"I'm relieved," Ganz said after the verdict was announced. "Obviously, this case has taken a long time both to solve and then through the court process. I think the victim's family deserves this, and I feel bad for them that it took this long."
"I'm very disappointed, obviously," said Bassan, a former public defender who has represented Davis since shortly after police identified him as the suspect in 2002. "It's a difficult case any time DNA is involved, and we conceded that it was his DNA."
"I think the evidence gave a pretty solid argument," Bassan added, that Davis did not have sexual contact with Martz the day of the murder. He added that he still believes in his client, who has been imprisoned since the early 1990s for crimes including robbery and an assault committed in prison.
"I didn't know Mr. Davis in 1985, but I've known him for 14 years," Bassan said. "I truly believe he's a good, decent person. He's been a remarkable person to work with. His character is one that I would have no problem with him coming to my home tomorrow, and I just wish that was possible."
The verdict marks Davis' second conviction for Martz's murder and the second time Bassan failed to persuade a jury that the prosecution's forensic evidence was faulty. A Superior Court jury first found Davis guilty in 2007.
A state appeals court overturned the conviction in 2010 and ordered a new trial, in large part because of juror misconduct. During deliberations, members of the panel had performed their own calculations on the likelihood of one of Davis' four brothers being a match for the DNA in the case, a violation of rules that direct jurors to consider only evidence presented during trial.
San Francisco prosecutors' appeal of that ruling took until 2013 to resolve, at which point Davis was transferred from state prison to city custody to await new proceedings.
The current trial began Jan. 11 before Superior Court Judge Jeffrey Ross.
One of those testifying for the prosecution was Spillane, the homicide inspector who began working the case in 2002.
He said after the verdict Thursday that he identified with Martz, a native of Massachusetts who had studied photography at Vermont's Goddard College and had come west in the late 1970s to attend the San Francisco Art Institute. She had traveled widely, including extended visits to Peru and Nepal she documented in her photography. In early 1985, she bought a small house on 25th Street.
"She was doing the right things, all the things that a young person of that age is supposed to be doing," Spillane said. He recalled that in the mid-1980s, when Martz was killed, "I was the same age. I was pretty much at the same juncture in my life. I was newly married and looking forward to my future."
He said he developed a bond with Martz's mother, Elsa, and other family members. Elsa Martz, a Maine resident who died in 2014, had stayed in touch with police in the years after the killing to ensure the case wasn't forgotten.
"Her mom, her sister, her brother, her boyfriend at the time, her close friends, her roommate -- they were such good, decent people," Spillane said. "... I probably got a little too much involved in this case than I had in others, but I'm glad that I did."
David Martz praised police and prosecutors for their handling of the case.
"I do want to express our gratitude and appreciation for the thorough and caring way Assistant District Attorney Andrew Ganz prosecuted Barbara's case and for the unflagging dedication of Jim Spillane, Lt. Tom Buckley and the San Francisco Police Department to bringing Barbara's killer to justice," he said.
Buckley, a beat cop in the Potrero Hill neighborhood at the time of Martz's murder, was later instrumental in getting the department to develop the DNA profile that led investigators to Davis.
Spillane said his own satisfaction with the trial's outcome is bittersweet.
"The defendant in the case I think never really had any kind of a shot at a decent life based on his upbringing or lack thereof," Spillane said. "He's going to be in prison for the rest of his life, but I think that's really the only place he can be. I don't think he can function in society."
Spillane said the Martz family "is happy they have some modicum of justice. But at the same time, they don't have Barbara."
Bottom line, he said, "I'm not jumping through the ceiling with joy on this. But I'm happy in the knowledge that no other family or group of people will have to experience the horror and the loss that this group of people have."