Drew Peterson, the former Bolingbrook police sergeant who was convicted in 2012 of killing his third wife, is set to return to court this month after a judge agreed to hear his motion to vacate the verdict.Will County Judge Edward Burmila scheduled the Jan. 21 hearing after finding a “gist of a constitutional” claim in Peterson’s six-page handwritten motion, according to the Chicago Tribune. Burmilla assigned Peterson a public defender and two investigators from the public defender’s office.Peterson …