A south suburban man was released Sunday after turning himself in to police the day before in connection with the beating and robbing of an off-duty Chicago police sergeant in the Loop on Thursday, reports the Chicago Tribune .
Brian Williams, 21, of Hazel Crest, was one of four people who were held in connection with the incident, according to a law enforcement source. Williams was released from Area Central detectives headquarters about 2 p.m. Sunday, said his attorney, Max Solomon.