FILE - In this Dec. 20, 2012 file photo, former Masachusetts state drug lab chemist Annie Dookhan sits in Suffolk Superior Court before her arraignment in Boston. Dookhan, who allegedly admitted faking test results in criminal cases, is expected to plead guilty Friday, Nov. 22, 2013, to obstruction of justice, perjury and tampering with evidence charges in a scandal that has jeopardized thousands of convictions. (AP Photo/Steven Senne, File)
FILE - In this Dec. 20, 2012 file photo, former Masachusetts state drug lab chemist Annie Dookhan sits in Suffolk Superior Court before her arraignment in Boston. Dookhan, who allegedly admitted faking test results in criminal cases, is expected to plead guilty Friday, Nov. 22, 2013, to obstruction of justice, perjury and tampering with evidence charges in a scandal that has jeopardized thousands of convictions. (AP Photo/Steven Senne, File) Credit: Steven Senne

BOSTON — The highest court in Massachusetts is being asked to vacate the pleas of 64 people who pleaded guilty to drug charges before the state’s scandal-plagued drug lab was able to test the substances. Tests later showed the substances were not illegal drugs, according to a statement from Suffolk District Attorney Rachael Rollins.

Annie Dookhan and Sonja Farak, drug chemists at the Hinton Lab in Boston from 2003 until 2012, were convicted of tampering, leading to the dismissal of tens of thousands of drug charges.

“In these specific cases, 64 defendants engaged in … plea bargaining without knowledge of evidence of their innocence or the gross misconduct in the Hinton Lab,” the statement said.

They have suffered the consequences of having a criminal record even after their release, the DA said.

If the Supreme Judicial Court vacates the pleas, the district attorney’s office will move to dismiss the cases and even have the defendants’ records expunged.