About 2,400 Stanislaus County drug cases may have been tainted by a crime lab analyst suspected of tampering with methamphetamine evidence, District Attorney Birgit Fladager said Friday.
In addition to meth cases, there are charges and convictions for prescription drugs, marijuana, cocaine and other illegal substances going back four years.
Court clerks will spend the weekend pulling the files. Letters will be sent to defense attorneys whose cases involved the analyst under investigation.
"It's certainly something you wish would never happen," Fladager said. "But it feels better now that we can take action."
Stanislaus County is one of five counties, including Merced, San Joaquin, Calaveras and Tuolumne, that use the Central Valley Crime Lab in Ripon.
Merced District Attorney Larry Morse said a cursory review found 550 county cases handled by the suspended lab employee.
"Some we'll undoubtedly have to dump," Morse said. "We certainly don't want any tainted convictions. If there's even a hint of skepticism of how legitimate a conviction is, we're going to undo it."
A spokesman at the San Joaquin County district attorney's office did not return a call seeking comment Friday.
The technician, one of five people who perform drug analysis at the Ripon crime lab, is on paid leave pending the results of a state Justice Department probe announced Thursday. Each analyst handles about 2,000 testing requests a year.
Seven methamphetamine samples handled by the analyst, who has not been identified, weighed less than originally reported. Officials have not said whether they suspect the analyst of stealing the drugs or inflating numbers on the reports.
John Myers, a professor at the University of the Pacific's McGeorge School of Law, said the allegations cast a pall over the integrity of the entire Ripon lab unless officials can narrow the scope of any possible impropriety.
"It's all a field day for the defense," Myers said. "If I'm a defense attorney, I'm going to say, 'My guy had baking soda.' And because your procedures are inadequate, how do we know? There are a million possibilities of things that could have gone wrong."
In 2005, the Ripon lab faced scrutiny after a staff member misidentified a diet supplement taken from a Lodi man as methamphetamine.
"They were kind of on the radar after that," said Modesto defense attorney Frank Carson.
Case not uncommon
Ralph Keaton, who heads an accreditation group for forensic labs, said he hears of one or two instances similar to the Ripon case each year.
He said analysts often work independently on drug cases but have colleagues review their work.
"Most of the time, my experience is their analytical work and reports are correct," Keaton said. "But after they've done the analysis, they will remove some portion of the (drug evidence)."
The usual giveaway is employees who show unusual behavior changes, Keaton said.
In the case of San Francisco lab technician Deborah Madden, who is accused of stealing cocaine evidence, Assistant District Attorney Sharon Woo complained in an e-mail of Madden's spotty attendance and her failure to testify in court.
The Ripon lab director, John Yoshida, was one of two people in charge of auditing the San Francisco lab in the Madden case. Yoshida criticized the lab's practices in a report released late last month.
"The stress and strain of trying to meet the demands of court has resulted in sacrificing quality for quantity," the report read. "This is evident throughout the laboratory processes used in the controlled substances unit; and, possibly provided the opportunity for evidence tampering and abuse of the evidence control system."
The Associated Press contributed to this report.
Bee staff writer Merrill Balassone can be reached at 578-2337 or email@example.com