The case is based solely on DNA evidence. The public defender wants the judge to release a memo which they hope will destroy the prosecution's case.
"I think there are some underlying issues which may be fairly significant," said Deputy Public Defender Bicka Barlow, speaking about the San Francisco Crime Lab's DNA testing unit. More specifically, Barlow points to a memo which noted DNA expert Rockne Harmon wrote early last year, criticizing the crime lab.
Harmon, who worked on DNA evidence in the OJ Simpson trial, wrote the memo when he was hired as a consultant to the San Francisco District Attorney's office.
Harmon's report was critical of DNA lab supervisor Cherisse Boland for her handling of evidence in a murder trial.
"There was an acquittal," Barlow said. "It was a homicide case. Her credibility became a very big part of the trial, and she actually -- in that trial -- made mistakes in her report that no one in the lab had caught until she was on the stand and testifying."
Harmon wrote the report after the defendants were acquitted, but the memo was never released publicly.
That memo has now become a central issue in the cold case murder trial of James Mayvield, who was arrested two years ago at a Bayview Church where he was a deacon.
Mayfield is charged with the murder of Jenny Read, who was bound, raped and stabbed in 1976.
"The only evidence linking the defense to the crime is the DNA, and the analyst who did part of the testing in that case -- Cherisse Bolad -- is the one who was being critiqued in the memo," Barlow said.
The lab also came under fire last year when the public defender's office received an anonymous letter revealing that some DNA samples had been switched by accident and that the lab kept the mix-up quiet for nearly two years.
"What we're seeing is a repeated pattern of hiding these things until something significant happens," Barlow said.
The District Attorney did not make the memo public, but he has now given it to the judge, saying he should decide if the memo has any relevancy in the Mayfield case.
The captain in charge of the crime lab says the analyst followed accepted DNA procedures in the former murder case.
Both offices declined on-camera interviews.