Update:

Disgraced former state chemist Annie Dookhan is now behind bars, after she pleaded guilty Friday to all 27 counts against her related to the drug lab crisis.

Dookhan showed little emotion and spoke softly as she pleaded guilty.

After accepting Dookhan’s plea, Judge Carol Ball sentenced her to three to five years in state prison in Framingham.

Prosecutors had sought a five- to seven-year sentence. Dookhan had sought a one-year sentence.

Original story:

BOSTON — A former state chemist is expected to go to prison Friday for a drug lab crisis that’s created turmoil throughout the Massachusetts criminal justice system.

Ex-chemist Annie Dookhan, 36, is scheduled to plead guilty Friday to falsifying drug tests and potentially compromising tens of thousands of criminal cases.

Her actions allegedly caused what may be the nation’s largest forensic testing scandal.

Massachusetts officials identified more than 40,000 criminal cases affected by testing Dookhan did during the nine years she worked at the now-closed Hinton state lab.

Michael O’Keefe, president of the Massachusetts District Attorneys Association, says prosecutors have sifted through hundreds of cases and close to 350 people have been released from prison.

“Prosecutors have been very reasonable about this,” he said, “dealing with a problem that is not of our making and that has to be addressed by balancing individual liberty and public safety.”

But defense attorneys are quick to point to documents from the Dookhan investigation showing that some prosecutors would often contact her directly and Dookhan would try to get their tests done quickly. One prosecutor resigned after his emails with Dookhan became public.

Anne Goldbach, of the Massachusetts public defenders agency, says forensic scientists are supposed to be impartial.

“You can tell that Annie Dookhan felt a sense of allegiance to the prosecution,” she said. “That is absolutely unconscionable.”

The documents in the case also show that for years Dookhan tested thousands more drug samples than her colleagues. A WBUR analysis shows that between 2009 and 2010, the time it took Dookhan to conduct a test went down by more than half.

“She continued to decrease the turnaround time,” said Tom Workman, a defense attorney and forensic expert. “You scratch your head and say, ‘How could someone do that?’ The obvious answer that comes to mind is they weren’t doing the work, they were dry-labbing.”

Dry-labbing is when a chemist just looks at a sample, with no actual testing involved. State Police say Dookhan admitted to dry-labbing when they questioned her about a year ago.

After Dookhan’s arrest, five of her coworkers and the state public health commissioner, John Auerbach, resigned. Auerbach admitted that his department, which oversaw the Hinton Lab, was at fault.

“I want to be absolutely clear,” he said. “I accept no responsibility for the actions of a rogue chemist, but I do think the Department of Public Health’s managers erred in lacking proper oversight of the forensic drug laboratory.”

Still, the question remains: Why did she do it? There is little in Dookhan’s history to provide an answer.

She’s the only child of immigrant parents who were proud of their daughter’s accomplishments. Her lab supervisors described her as a valuable member of the team.

The American Civil Liberties Union of Massachusetts says a trial might have shed light on her motivation.

“By pleading guilty, Annie Dookhan has taken a step,” said Matt Segal, Massachusetts ACLU’s legal director, “which means that there won’t be a trial, there won’t be a public airing of the evidence against her and the evidence that might exist against anyone else.”

During a recent hearing, Dookhan’s attorney, Nicholas Gordon, said his client made mistakes trying to be the top chemist — and then tried to cover up those mistakes.

“Her motivation is to be the hardest working and most prolific and most productive chemist that she could possibly be, and that’s how this whole mess begins,” he said.

Gordon also said Dookhan is now divorced and the primary caretaker of her 7-year-old disabled son. So he asked the judge for a one-year prison sentence. Prosecutors asked for significantly more, citing the millions of dollars the state has spent to deal with the scandal. The judge said she would not exceed a three- to five-year sentence for actions she described as “shaking the criminal justice system to its core.”