The tape recorder started rolling as two police investigators sat in their car in a hospital parking lot with Deborah Madden on Feb. 26. "You're causing a huge nightmare for the city," said one officer.
Now the 60-year-old technician and the obscure police crime lab where she worked for 29 years stand at the center of a scandal that has led to the dismissal of hundreds of criminal cases and jeopardized thousands more. Police have accused Madden of skimming cocaine evidence from the lab, but she hasn't been criminally charged in the case.
Forensics experts say Madden is not the first crime lab worker suspected of stealing drugs or other illegality, and San Francisco's lab joins several other cities in suffering a loss of credibility.
A Houston man was awarded $5 million last year after spending 17 years in prison on rape charges overturned because of a discredited criminal lab.
Detroit shut down its crime lab in 2008 after outside auditors uncovered serious errors in the way evidence was handled.
"It's real hard to build a good reputation and it's very easy to destroy it," said Ralph Keaton, executive director of the American Society of Crime Laboratory Directors. "And it takes even longer to rebuild it."
The fallout from San Francisco's lab scandal is still unfolding and experts say it could take years to clean up, especially if authorities fail to establish which criminal cases were compromised.
"I don't think we have a full grasp on the magnitude of this yet," said Jim Norris, former head of the lab. "A lot of this runs on trust that the lab results have been correct, but now people don't think they are. So the whole system has grinded to a halt."
Madden's attorney, Paul DeMeester, said last week that her February talk with police was honest and forthright, and she "talked about all of the wrongdoing she had committed at the lab, which is very minimal."
In the taped interview, investigators pleaded with Madden to confess to skimming significant amounts of cocaine from drugs seized during arrests. A confession, they said, would take pressure off co-workers who also were being questioned and would help begin to repair the damage.
"And it will take years for the people in that lab and the San Francisco Police Department to come back from that, even if it's one person," Inspector Peter Walsh told Madden on the tape. "If it's a mistake, you just need to tell us it's a mistake."
"I didn't do it," she said, admitting only to snorting small amounts of cocaine spilled on her work station.
An internal review turned up significant shortages of drug evidence in several cases she handled. But Madden said she was not surprised by that because weight discrepancies occurred frequently at the lab.
San Francisco's 13,500-square foot crime lab, on a former U.S. Shipyard in the rough Hunter's Point section of the city, is five miles from headquarters.
"A converted warehouse in the middle of nowhere on a toxic dump site," said Fred Tulleners, a former California Department of Justice crime lab manager. "The forensic scientists in San Francisco have been working in abysmal conditions."
The drug unit employed Madden, two other criminalists and a supervisor.
Madden's co-workers said they got along with the San Mateo woman, but that she displayed increasingly bizarre behavior in the last months of 2009 culminating with a stint in an alcohol rehabilitation clinic.
Madden, who lives alone with two dogs and a cat, appeared beset with personal problems.
A jury convicted her in 2008 of domestic violence and vandalism in neighboring San Mateo County for opening a gash on her longtime partner's forehead with a thrown telephone, records show. Madden called the incident during their breakup an "unfortunate accident," enrolled in an alcohol treatment program and was sentenced to 30 days in jail.
Police now concede they had a legal requirement to disclose the conviction to defense lawyers handling drug cases Madden analyzed. And the omission is expected to play a role in attempts by some prisoners to have their convictions overturned.
By late last year, Madden's behavior and job performance were attracting attention outside the lab, according to records.
San Francisco Assistant District Attorney Sharon Woo sent a Nov. 19 e-mail to Chief Assistant District Attorney Russ Giuntini complaining of Madden's behavior. Woo said Madden appeared to be purposely sabotaging cases by calling in sick on days she was to testify in court.
The e-mail and the transcript of the tape were among 1,000 pages of documents in the case made public by prosecutors following a judges order.
San Francisco District Attorney Kamala Harris, who is vying for the Democratic nomination for state attorney general, said she was unaware of any serious problems at the lab until just recently.
The police department was tipped off to problems at the lab on Dec. 16 when Madden's sister notified Madden's direct supervisor that she had found a vial of cocaine on her sister's dresser.
The supervisor, Lois Woodworth, told police Madden had begun to act erratically in September 2009. Woodworth said Madden was arriving late to work and staying alone after hours, but not claiming overtime. Woodworth also confronted Madden with evidence that she had rummaged through a colleague's evidence locker without permission.
Police did not question Madden until Feb. 26. Then Police Chief George Gascon shuttered the lab on March 9, and testing was farmed out.
Assistant Police Chief Jeff Godown, who this month took over the lab's supervision, said the lab has suffered from mismanagement, as recent audits also have found. "It's just going to take some time" to repair the damage, he said.
Madden was arrested March 3 after investigators found one-tenth of a gram of cocaine and a gun at her house. Madden has pleaded not guilty to a felony cocaine possession charge in San Mateo County Superior Court.
"One person went sideways and now that's tarnishing everybody's work," said Tulleners, the forensic science director at the University of California-Davis. "Ideally, the next best step would be for the state take over that lab. But I doubt that will happen, not in this current budget crisis."