One chapter in a Massachusetts police lab scandal closed Friday with the sentencing of disgraced former state chemist Annie Dookhan to three to five years in prison after pleading guilty to 27 counts of obstruction of justice, perjury, tampering with evidence and other charges.

But the state continues to reel from the fallout of the wide-ranging fraud, in which Dookhan lied about the presence of drugs in test samples over a nine year period. A state investigation of her work at the Hinton State Lab in Boston's Jamaica Plain neighborhood showed that Dookhan falsified tests, forged initials of an evidence officer to cover-up her misconduct, lied about her academic credentials on the stand during trials in which she gave expert testimony and other crimes.

The state believes as many as 40,323 cases may have been compromised by Dookhan during her tenure. The ACLU believes that number may be much higher, since the now-closed Hinton lab handled more than 100,000 cases while Dookhan worked there. The ACLU has pressed for a faster resolution of the backlog of review of Dookhan cases, and is calling for the dismissal of all cases that do not involve violent crime or weapons offenses, that involve a police officer or prosecutor who, at any time, communicated directly with Dookhan, or that involve a defendant who has served at least half of his or her sentence.

"The Massachusetts drug lab scandal has tainted as many as 190,000 cases," said Matthew R. Segal, legal director of the American Civil Liberties Union of Massachusetts. "But the approach to addressing the crisis taken by the Commonwealth and the Essex County District Attorney--retrying cases one by one, and keeping defendants in prison while they wait in line for court hearings--has worsened it."

Hundreds of criminal convictions have already been set aside as a result of the scandal. Several of those who had been convicted on evidence handled by Dookhan and released have since been re-arrested for new crimes, including one murder.

“Annie Dookhan’s egregious misconduct sent ripple effects throughout our entire criminal justice system,” said Massachusetts Attorney General Martha Coakley. “Her deliberate decision to tamper with drug evidence and fabricate test results harmed the integrity of the system and put the public’s safety at risk.”