A chemist whose alleged mishandling of drug samples led state police to shut down a crime lab testified in 2010 that she was in charge of quality control at the lab.
Some defense attorneys say the revelation could raise questions about far more than the 50,000 samples she is known to have tested.
State police closed the lab on Aug. 30 after their investigation showed that the chemist, Annie Dookhan, failed to follow testing protocols and may have deliberately mishandled drug samples.
State police have said they don't know how many samples may have been tainted.
A transcript obtained by The Associated Press of Dookhan's sworn testimony in a 2010 Suffolk County trial shows Dookhan testified that she ran "quality control/quality assurance" within the lab.