The fallout continues in Massachusetts where a former crime lab chemist allegedly tampered with evidence from drug tests for years. Authorities say Annie Dookhan may have tampered with evidence in up to 40,000 cases. This means that thousands of people may have been falsely convicted. Several hundred convicts have already been  released. The scandal is calling attention to the deleterious state of crime labs throughout the country.   Sarah Birnbaum, state house reporter for WGBH Radio in Boston, has been covering the Annie Dookhan drug lab scandal.  Marvin Schechter, defense attorney in New York City, served as an adviser to the National Academy of Sciences forensics 2009 report "Strengthening Forensic Science in the United States: A Path Forward." "There is this chemist named Annie  Dookhan, and she allegedly tainted evidence in the nine years she worked in the state lab in Massachusetts," Birnbaum says. "She admitted to things like sprinkling heroin or cocaine in whatever she was testing so the test would turn out positive, and also grabbing a pile of 25 drug samples, and testing five of them, and then listing them all as positive." "I think it goes beyond just a  rogue chemist," Birnbaum says, citing a number of other problems with the lab where  Dookhan  worked, including a lack of proper supervision, and a backlog of cases that would have taken a year to catch up on.   Though it remains unclear what  Dookhan's  motivation was, the current wisdom is that she wanted to seem like a super-worker. "She was also testing about 9,000 drug samples where everyone else was testing about 3,000," Birnbaum says.   "The scope is enormous," Birnbaum says. "She handled about 60,000 drug samples, and it could jeopardize 34,000 criminal cases. But it goes beyond that. She had unsupervised access to the drug locker where everyone else kept their evidence, and the concern is that the state has to pay to retry thousands upon thousands of  defendants." The case also goes beyond just drug offenses. There are also many people who are serving longer sentences for other crimes because of prior offenses, based on evidence from Annie  Dookhan's testing.   Governor Deval Patrick  has hired a former prosecutor to attempt to sort out the  mess, but the implications of this go even beyond the cases handled by Annie Dookhan.   "You don't have the certainty that the evidence being presented to the jury is legitimate evidence," Schechter says. And the scariest part? That this is not just a rogue person, but a systemic problem of a lack of supervision.