Houston: An Indian-American former chemist at a Massachusetts drug lab has been sentenced to prison for faking forensic test results, a scandal that has jeopardized thousands of convictions.

Annie Dookhan pleaded guilty on Wednesday in Suffolk Superior Court to all 27 counts against her related to the drug lab scandal. She was sentenced to three to five years in prison.

Dookhan, 36, showed little emotion and spoke softly as she pleaded guilty.

After accepting Dookhan's plea, Judge Carol Ball sentenced her to three to five years in state prison in Framingham.

Dookhan's falsification of drug tests, in an attempt to look like a highly productive employee, prompted the release of hundreds of convicts, raised questions about thousands of cases, and forced the state to spend millions to address the problems.

Ball, who found that Dookhan had entered her plea "freely, willingly, and voluntarily", also sentenced Dookhan to two years of probation.

Prosecutors had requested a five-to-seven-year sentence for Dookhan. Her defense attorney had argued for a maximum sentence of one year.

Sentencing guidelines called for a maximum sentence of three years for Dookhan, but Ball said in a ruling last month she wanted to impose a tougher sentence "given the magnitude of the harm she has done, considerations of general deterrence and, particularly, punishment."

Massachusetts officials identified more than 40,000 criminal cases affected by testing Dookhan did during the nine years she worked at the now-closed Hinton state lab.

Michael O'Keefe, president of the Massachusetts District Attorneys Association, says prosecutors have sifted through hundreds of cases and close to 350 people have been released from prison.

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