A tear runs down the cheek of former state chemist Annie Dookhan during a hearing Friday, Nov. 22, 2013, in Suffolk Superior Court in Boston, where she
A tear runs down the cheek of former state chemist Annie Dookhan during a hearing Friday, Nov. 22, 2013, in Suffolk Superior Court in Boston, where she entered a guilty plea on charges of obstruction of justice, perjury and tampering with evidence. Dookhan, who admitted faking test results in criminal cases, was sentenced to three to five years in prison, followed by two years' probation. (AP Photo/The Boston Globe, David L Ryan, Pool) (David L. Ryan)

BOSTON (AP) -- An investigation has found a rash of problems at a now-closed Massachusetts drug lab shut down after a chemist admitted faking test results in criminal cases, throwing the state's legal system into turmoil.

The report released Tuesday by the Massachusetts Inspector General found that although chemist Annie Dookhan was the "sole bad actor" at the lab, management failures, "wholly inadequate training," and a lack of uniform protocols contributed to Dookhan's ability to commit "acts of malfeasance."

Dookhan is serving a prison term of up to five years after pleading guilty to charges including obstruction of justice.

State police shut down the Department of Public Health lab where Dookhan worked in 2012 after discovering the extent of her misconduct.

Courts have been flooded by thousands of requests for new trials and dismissals.