Debra Madden, 62, appeared is in federal court to plead guilty to misdemeanor possession for taking cocaine from the crime lab in 2009.
The lesser charge that results in a plea deal carries a maximum one-year sentence. Madden's two previous trials on the more serious charge in Illston's court ended in mistrials in October and January with jurors unable to agree on a verdict.
Because of the scandal about 500 San Francisco drug-related cases were dismissed.