According to The Chronicle, San Francisco police has managed to launch a criminal investigation into a drug lab technician Deborah Madden, 60, who is suspected of stealing cocaine evidence, though her sister believes that the woman has taken away a bottle full of the same.

It took about two months for the police to initiate a probe into the matter. The delay might have led to the destruction of hundreds of narcotics prosecutions in San Francisco, as drugs were verified at the lab after doubts arose about the technician as well as the Police Department's potential to guarantee the integrity of seized evidence.

Though, Madden has not been charged with a crime related to theft of evidence at the lab, but there are doubts that she stole and used cocaine. She accused that the other people working in the lab were careless in their work which prompted the police to shut down the lab on Tuesday.

Madden’s sister found cocaine at Madden's San Mateo home in December when Madden was away in an alcohol rehabilitation program, according to the law enforcement officials. She contacted the police on Dec 16 but before police could test the vial, she took it to Madden's rehabilitation counsellor, who managed to destroy the same.

Madden clarified it to the police investigators that she started using cocaine in October and took only the residual of cocaine that was left on the wax paper that lab technicians use when they weigh samples.