More than 80 San Francisco police officers have criminal histories or misconduct records that the Police Department withheld and prosecutors did not disclose to defense attorneys in cases in which officers testified, a failure that could put hundreds of felony convictions in jeopardy, The Chronicle has learned.

The potential fallout could be far more severe than that caused by the cocaine-skimming scandal at the San Francisco police drug lab, which prompted prosecutors to dismiss more than 600 narcotics cases, experts say.

"We are not potentially talking about possession of cocaine cases - we are potentially talking about very serious felonies," said Lael Rubin, a prosecutor with the Los Angeles County district attorney's office who oversees that county's disclosure process and leads training seminars on the subject for prosecutors in California.

"Depending on the nature of the failure to disclose (an officer's crimes) and the officer's role in the particular case, it could result in very serious cases being tossed out and serious offenders being released on the street," Rubin said.

"This is huge," said San Francisco Public Defender Jeff Adachi, whose lawyers represent the majority of felony defendants tried in the city. "It will make the problems at the crime lab look like small potatoes."

District Attorney Kamala Harris' spokesman, Brian Buckelew, said prosecutors are doing everything they can to rectify problems in what he described as an "imperfect" process of disclosing officers' backgrounds to defense lawyers. Harris did not make herself available to answer questions Monday.

"We are looking forward to getting the information and assessing what it means," Buckelew said, "and, if necessary, redressing any problems."

Police Chief George Gascón said he is "obviously concerned" about his department's failure to disclose the officers' histories. "I want to make sure the Police Department adheres to both its ethical and legal obligations," he said.

Legal obligation

Under the law, prosecutors are responsible for alerting defense attorneys when any witness, including a police officer, has been arrested or convicted for a broad range of crimes, or accused of misconduct for such disciplinary offenses as lying during internal affairs interviews. Police officers can keep their jobs even if they have been convicted of misdemeanors, but their histories must be disclosed so defense lawyers have the opportunity to discredit their testimony on the basis of their character.

Los Angeles prosecutors were the first in the state, in 2002, to develop a written policy that sets out how prosecutors alert defense attorneys to arrests and convictions involving officers and civilian police experts testifying in criminal cases. They also keep files on certain police disciplinary cases.

Many other counties have since adopted such policies, but San Francisco has not, preferring to rely on police to volunteer information.

Madden case

That has already proved problematic in the case of Deborah Madden, the retired civilian technician at the police crime lab suspected of skimming narcotics evidence.

Madden was convicted of misdemeanor domestic violence in 2008 and went on to testify in an unknown number of criminal trials. Harris' office never ran a check on her record and did not tell defense attorneys about her conviction, and several lawyers whose clients were found guilty are now seeking to have those cases overturned.

Harris' office has said it was the Police Department's job to pass along its employees' criminal histories, although the legal onus is on district attorneys to check with police and inform defendants. San Francisco prosecutors conceded they never asked police for the information.

Federal prosecutors did ask the Police Department about Madden as part of a drug-racketeering murder case last year, according to U.S. Attorney Joseph Russoniello, but the department did not tell them about her criminal record.

Problem comes to light

In mid-April, Judge Anne-Christine Massullo confronted Harris' prosecutors on the Madden issue and asked if the office had a written policy.

Chief Assistant District Attorney Russ Giuntini then wrote a letter to Gascón saying a Police Department lawyer had revealed April 6 that there were more than 30 officers with criminal histories that would have to be disclosed. In the letter, which The Chronicle obtained under the state Public Records Act, Giuntini asked the department to provide details.

A subsequent, more comprehensive police review has so far turned up roughly 80 officers whose records could be used as fodder by defense attorneys, sources close to the matter said.

The officers' names have not been released. Harris' office has yet to receive a complete list, so prosecutors have no idea how many of the officers have testified against people who eventually were convicted.

Adachi, however, pointed out that officers routinely testify in any cases in which they have arrested the defendant. "We won't know until we can actually look at convictions of these officers," he said, but he believed at minimum, hundreds of cases could be open to question.

"It is the district attorney's job to check the criminal history of every witness, and they obviously didn't do that," Adachi said. "Every San Franciscan should be outraged here."

Court precedents

Prosecutors' obligation to turn over officers' criminal histories does not end with a trial.

One conviction that was reversed on appeal involved a California Highway Patrol officer who testified in a Southern California drunken driving accident case in 1990. The CHP investigator was disciplined a year after the trial for using incorrect speed-calculation formulas in several other accident cases.

The appellate court overturned the defendant's drunken driving conviction, finding that even when disciplinary action follows a trial, prosecutors had the duty to disclose facts that would cast doubt on a witness' reliability.

Clifford Gardner, an adjunct faculty member of UC Berkeley's Boalt Hall law school who specializes in appeals, said courts have been receptive to overturning convictions under a 1963 U.S. Supreme Court decision involving disclosure of witnesses' pasts, Brady vs. Maryland.

"If the witness is important and the evidence impeaches the witness," Gardner said, "Brady usually is going to require reversal."

What happens now

Giuntini's letter to police is the first step in the process that would enable Harris' office to compile a database of officers with arrests, convictions or other problems, then cross-reference with court records in which the officers have been witnesses. Then, prosecutors would alert defense attorneys in those cases.

"We've implemented a uniform Brady program internal to the (district attorney's) office," spokesman Buckelew said, "that identifies, centralizes and ultimately disseminates, in appropriate cases, Brady information."

The head of the police officers union, Gary Delagnes, said he is in talks with Gascón to develop a policy of what must be disclosed to defense attorneys.

"We'll be part of the solution," Delagnes said.

Rubin, who oversees such an effort for the Los Angeles district attorney, said police cooperation is key to making the system work.

"We get the cooperation of law enforcement - they get it," Rubin said. "They don't want cases thrown out because of the failure to turn over necessary information."

Buckelew said the district attorney's internal review is going on even as Harris' office awaits notification from the Police Department on officers who had problems that should have been disclosed.

He said the way San Francisco has been doing it, although similar to the system used in "numerous other counties in California," is inadequate.

"There simply has to be a more formalized mechanism of identification and notification," Buckelew said. "It's too important."