District attorneys in Massachusetts are asking the state's highest court to dismiss thousands of drug cases that were tainted due to misconduct by drug lab chemist Sonja Farak.

Farak pleaded guilty in 2014 to stealing and using drugs from the state crime lab at UMass Amherst.

District attorneys continue to compile lists of defendants whose cases they’ve recommended for dismissal, but more than 6,000 cases are expected to be thrown out.

“What it says about the cases is that we no longer can trust the integrity of the drug test and that therefore the convictions stand on very shaky ground,” said WGBH News legal analyst Daniel Medwed.

It’s the second time in less than a year that the state's prosecutors have been forced to throw out thousands of cases due to misconduct by drug lab chemists. More than 20,000 convictions were tossed in April after another chemist, Annie Dookhan, was caught tampering with evidence and falsifying tests.

“It does seem like the prosecutors have learned their lesson a little bit from Dookhan in that they responded with a little more alacrity here and were a little quicker to dismiss the cases,” said Medwed. “They only did so previously after lengthy, extensive litigation.”

ACLU staff attorney Carl Williams said even though probably all of the defendants convicted with evidence tainted by Farak have already served their sentences, throwing out the convictions will help them get on with their lives.

"It can affect their driver's license, it can affect the ability to get a student loan,” Williams said. “It can affect the ability to have public assistance, get any job, to get a law license, to be accepted to a school.”

Attorneys for the ACLU and the state public defender agency say their clients weren't just victims of misconduct by Farak, but also by state prosecutors and the Attorney General's office. A trial judge found that two former assistant attorneys general misled the court and "tampered with the fair administration of justice" by withholding evidence about the scope of the chemist's misconduct. Attorneys say prosecutors also failed to notify the people whose cases were tainted by Farak until they brought the matter to the state's highest court.

“Prosecutors from the Massachusetts attorney general's office actually misled the courts and the people of Massachusetts about the scope of the scandal,” said Carol Rose, executive director of the ACLU of Massachusetts. “Worse, when the evidence of tampering came to light, Massachusetts-elected district attorneys again failed to notify thousands of people who had been wrongfully convicted by the tainted evidence, until we sued.”

“The lawyers entrusted with ensuring the integrity of the justice system are the very ones who corrupted it,” said ACLU of Massachusetts legal director Matthew Segal. “Despite what the attorney general's office has done, we are now on the verge of delivering relief to thousands of people, but we won't rest until we also deliver justice.”

Lawsuits against the district attorneys and the attorney general are ongoing.

“It’s unfortunate that the ACLU chose to stage a press conference without reading the AG’s brief filed in this case, which calls for speedy relief for these defendants,” Jillian Fennimore, a communications director for Attorney General Maura Healey said in a written statement. “Sonja Farak’s crimes were egregious and, as our filings today make clear, this office has been working hard to resolve these cases as quickly as possible. Staff in the AG’s office have been working hard for months to review databases, identify the Farak defendants, and secure their speedy relief. For the ACLU to suggest otherwise is false and irresponsible.”

The Associated Press contributed to this story.