BOSTON (CBS/AP) – Massachusetts Attorney General Martha Coakley says the arrest of a former chemist at the center of the state drug testing lab scandal is just the beginning of the criminal investigation.

Annie Dookhan, 34, was taken into custody Friday at her home in Franklin. She’s charged with two felony counts of obstruction of justice and a misdemeanor count of lying about her resume.

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Dookhan’s alleged mishandling of drug samples prompted the shutdown of the Hinton State Laboratory in Jamaica Plain last month and resulted in the resignation of three officials, including the state’s public health commissioner.

State police say Dookhan tested more than 60,000 drug samples involving 34,000 defendants during her nine years at the lab. Defense lawyers and prosecutors are scrambling to figure out how to deal with the fallout.

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Since the lab closed, more than a dozen drug defendants are back on the street while their attorneys challenge the charges based on Dookhan’s misconduct.

At a news conference Friday afternoon, Coakley said that the investigation is continuing and Dookhan could face more charges.

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“This is the beginning of the criminal investigation charging process. She’s only facing three counts today, relating to two particular cases,” Coakley said.

“This is not the end of the charging.”

Coakley said Dookhan’s actions “totally turned the system on its head” and that there is no indication of criminal activity by anyone else.

“Today’s arrest is one step further towards making sure there is accountability for this corruption of the system,” the attorney general said.

“Our goal is to get to the bottom of what happened, to determine as best we can and as thoroughly as we can, why this chemist did this, as we believe, and for so long.”

Coakley said Dookhan has been cooperative in the investigation, but “we have not identified a motive.”

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