Annie Dookhan, a chemist at the Hinton State Laboratory in Boston, was loved by prosecutors — she was a whiz, testing more drug evidence than everyone else in the lab, and she always got them the results they wanted. Although some of her coworkers wondered just how she got it done, no one else was very concerned because she was helping put people in jail.

In 2011, someone in the lab noticed she’d forged the name of an evidence officer in a log book. Investigators started pulling that string, and when all was said and done charges against more than 21,000 people convicted of drug crimes were dropped and estimates were she may have falsified evidence in more than 40,000 drug cases.

Find out how Annie Dookhan went from being a shining star in the Massachusetts criminal justice system to the biggest fraud in Massachusetts history.

And as a bonus, the trailer for our new Groovy Tube podcast!