BOSTON (AP) — About 300 to 500 defendants, including some “pretty dangerous people,” may be released into Boston streets because of the alleged mishandling of evidence at a Massachusetts drug lab, a prosecutor said Friday.

Chemist Annie Dookhan is charged with obstruction of justice for allegedly skirting protocols and faking test results at the now-closed state drug lab. At least two dozen defendants whose cases Dookhan handled have been released, including career criminal and convicted rapist Marcus Pixley.