By MyFM's Rick Michaels - We will know today how many of the approximately 24-thousand tainted cases will be dismissed as a result of the damage caused by a former state drug lab chemist and Franklin resident. Annie Dookhan pleaded guilty to tampering with evidence and falsifying thousands of tests in criminal drug cases which called into question evidence used to prosecute the defendants. Today, Massachusetts District Attorneys will tell the State highest court how many of those cases will be thrown out. The American Civil Liberties Union is estimated some 20-thousand cases will be dismissed which could make it the largest mass dismissal of criminal convictions in U.S. history. Dookhan, who lived in Franklin at the time, pled guilty to 27-charges in 2013 and served three-years in prison.