BOSTON (AP) -- A former Massachusetts drug lab chemist at the center of a scandal that threatens to unravel thousands of criminal cases pleaded not guilty Thursday to charges including perjury and evidence tampering.
Annie Dookhan's arraignment on 15 charges in Suffolk Superior Court could be the first in a series of arraignments in other counties following a 27-count grand jury indictment Monday.
State prosecutors allege Dookhan fabricated test results and tampered with drug evidence while testing substances for criminal cases. Judges have released about 200 defendants from custody in the last few months and put those cases on hold. Many more cases could be affected.
Authorities say Dookhan tested more than 60,000 samples involving 34,000 defendants during her nine years at the lab. State police shut down the lab in August.
Dookhan, 35, made no comment to the media outside the Boston courtroom after she pleaded not guilty to eight counts of evidence tampering, five counts of witness intimidation, one count of perjury and one count of making a false claim of holding a master's degree.
In court, the Franklin woman stood behind her lawyer and blinked repeatedly while looking toward the magistrate's bench. "Not guilty," she replied to his questions about the 15 counts.
Magistrate Judge Gary Wilson agreed to change Dookhan's nightly curfew hour from 6 p.m. to 10 p.m. after her lawyer said the earlier hour was hampering the social life of a defendant who already was on GPS monitoring and had no criminal record.
"She's not a flight risk. It's certainly putting a damper on her ability to have any kind of a social life, interact with the neighbors and family and friends," defense lawyer Nicolas Gordon said.
Dookhan also remained free on $10,000 bail.
Afterward, Gordon said he hasn't seen all of the government's evidence "so it's too soon to comment" on aspects of the case.
"I'm told there's thousands of emails out there and I haven't seen them yet," he said.
Authorities alleged in court records Thursday that Dookhan once emailed a fake test result to a prosecutor for use in a criminal case, relying on a sample that had been gone from the lab for about six months.
Authorities have said Dookhan admitted to investigators she sometimes would "dry lab" samples, meaning she would test some samples for drugs and assume the others were positive. She also allegedly admitted she sometimes added a known narcotic to a sample to turn it positive if it tested negative.
In addition, authorities claimed Thursday that Dookhan testified 14 times that she had a master's degree in chemistry from the University of Massachusetts-Boston although investigators found she was never enrolled in classes at that level.
The only potential motive authorities say they can offer in the case is Dookhan's desire to be seen as a good worker.
Dookhan faced suspension from her lab duties in June 2011. Authorities alleged that dozens of drug samples weren't properly checked out of a safe and that Dookhan forged a colleague's initials to try to cover her misconduct.
She resigned in March during a Department of Public Health internal investigation. Amid that probe, state police took over the lab in July as part of a state budget directive.