Forensic chemist's addiction frees 7,680 convicted of drug charges in Massachusetts.

BOSTON, Mass -- A controversial case came to an end Thursday when the state supreme court ordered the dismissal of 7,690 drug cases thanks to the actions of an errant forensic chemist.

Sonja Farak, a forensic chemist who worked for the Massachusetts State Crime Lab in Amherst for eight years, had been stealing and abusing the drugs in evidence.

Massachusetts Supreme Judicial Court Justice Frank Gaziano issued an order dismissing all 7,690 cases, citing the evidence was tainted by Farak's wrongdoing.

Farak was fired and found guilty in court in 2014. She was sentenced to 18 months in prison. Prosecutors then began the painful task of trying to figure out how many cases would need to be thrown out. The number, initially thought to be around 6,000 actually turned out to be nearly 8,000.