CHICAGO (AP) — A judge in Chicago has thrown out the convictions of 15 men who say a corrupt Chicago police sergeant manufactured evidence that sent them to prison.

Cook County prosecutors made the request Thursday as 10 of the men stood before Judge Leroy Martin Jr.

It was the latest chapter in a scandal that resulted in former Sgt. Ronald Watts’ 2013 conviction for extorting money from drug dealers. State’s attorney spokesman Robert Foley says the office’s conviction-integrity unit is looking into dozens of other cases and identified a pattern suggesting “corrupt activity” involving Watts and “members of his crew.”

Joshua Tepfer of the University of Chicago’s Exoneration Project says he is “extraordinarily grateful” to the state’s attorney’s office.