(CBS) -- The Cook County State's Attorney is vacating the convictions of 15 men accused of narcotics offenses - convictions all linked to an ex-Chicago Police sergeant.
At the center of this: fired Chicago Police Sgt. Ronald Watts.
The state's attorney's office says it's been reviewing claims made by 15 people arrested by Watts from 2003 to 2008 and that "a review has shown a pattern of narcotics arrests that raises serious concerns about the validity of the resulting convictions for these 15 defendants."
Joshua Tepfer of the Exoneration Project -- attorney for the 15 -- says, "It's historic. This is, as far as I know, the first mass exoneration in the history of Cook County.
"There certainly were instances where multiple people were exonerated of the same crime for which they were convicted, but this is 15 different people and 18 different convictions that are being overturned in one fell swoop."
Tepfer says he's sure there are more exonerations to come.
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