Dookhan’s supervisors have faced harsh criticism for not removing her from lab duties after suspicions about her were first raised by her co-workers and for not alerting prosecutors and police. However, Coakley said there is no indication so far of criminal activity by anyone else at the lab.
Co-workers began expressing concern about Dookhan’s work habits several years ago, but her supervisors allowed her to continue working. Dookhan was the most productive chemist in the lab, routinely testing more than 500 samples a month, while others tested between 50 and 150.
One co-worker told state police he never saw Dookhan in front of a microscope. A lab employee saw Dookhan weighing drug samples without doing a balance check on her scale.
In an interview with state police late last month, Dookhan allegedly admitted faking test results for two to three years. She told police she identified some drug samples as narcotics simply by looking at them instead of testing them, a process known as “dry labbing.” She also said she forged the initials of colleagues and deliberately turned a negative sample into a positive for narcotics a few times.
Defense attorneys for drug suspects were not surprised by Dookhan’s arrest.
“I hope the system isn’t treating the evidence against her the way she treated the evidence against several thousand defendants,” said attorney John T. Martin, who has a client who was allowed to withdraw his guilty plea based on concerns over Dookhan’s work.
Dookhan was suspended from lab duties after getting caught forging a colleague’s initials on paperwork in June 2011. She resigned in March as the Department of Public Health investigated. The lab was run by the department until July 1, when state police took over as part of a state budget directive.
Niedowski reported from Franklin. AP writer Bridget Murphy contributed to this report.