SAN FRANCISCO — More drug-related cases were dismissed in San Francisco courtrooms Thursday, bringing to nearly 60 the number of cases thrown out over the past two days because of accusations of evidence tampering in the city's crime lab.
Assistant District Attorney Brian Buckelew said 25 to 30 cases were dropped Thursday as authorities investigate allegations that a longtime lab technician stole cocaine evidence last year. At least two dozen were dropped Wednesday, and Buckelew said up to 35 cases could be dismissed Friday.
Prosecutors may refile charges in the cases after evidence has been retested, he said.
Lab technician Deborah Madden, 60, took a leave of absence after a crime lab audit in December revealed drug evidence was missing. She retired March 1 after a 29-year career as a criminalist, most of which was spent in San Francisco.
Her job was to verify the weight and purity of seized drugs.
No charges related to the missing evidence have been filed.
Meanwhile, Police Chief George Gascon acknowledged Thursday that his department erred by not disclosing to the district attorney and public defender's offices that Madden was convicted of misdemeanor domestic assault in 2008.
"We made a mistake," Gascon said at a news conference. "We had a system failure."
Gascon also said that despite the department's shortcoming regarding Madden, it "should not be a reason to overturn hundreds or thousands of cases."
"This is a gross overstatement," he said.
But Public Defender Jeff Adachi said Thursday he's unsure not disclosing Madden's criminal record was an oversight.
"We have a number of cases where Ms. Madden testified (in court as an expert witness), and we were told she had no criminal history," Adachi said. "This is a situation where the integrity of a criminal conviction or an outcome in a criminal case could be compromised by what has happened."
Buckelew said it's likely Madden testified more than two-dozen times since her conviction.
On Thursday, Adachi sent a letter to District Attorney Kamala Harris requesting Madden's criminal record, any criminal cases she handled since 2000 and when the DA's office knew about the investigation into the missing evidence.
Buckelew said the DA's office learned in late February, shortly after Madden was interviewed by police.
"It's a real shame that one person could potentially do so much damage to the hard work done by police officers and prosecutors," Buckelew said.
Gascon said the interview with Madden was a "freewheeling conversation" that led to a police search of her home last week. Police discovered a gun and small amounts of a "white powdery substance" believed to be cocaine, Gascon said.
Madden was arrested and released on bail. She has not been charged.
Gascon also said drug testing on new criminal cases could take place at labs in other counties and by the federal Drug Enforcement Administration as early as Friday.
"Is it a costly experience? Absolutely. But I think it would be much more costly if we looked the other way," Gascon said.
Gascon said the city's crime lab remains shut pending another audit and added that Attorney General Jerry Brown's office will help with the police department's investigation.
At times, the seemingly unflappable Gascon appeared frustrated answering questions about the parade of many suspected drug criminals being let go.
"Look, I'm not downplaying that we released some people and some of them will not be readily available (for questioning)," Gascon said. "They're not going to come in willingly and say, 'Take me to jail.' I get that.
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"It is a bad situation."