Caption: Convicted killer Timothy Herring Jr. was 19 when he gunned on-duty Chicago police evidence technician Michael Flisk (top, left to right) and former CHA police officer Stephen Peters in November 2010.

A Cook County jury found a Chicago man guilty in the double slayings of an on-duty Chicago police officer and a former Chicago Housing Authority officer following a week-long jury on Wednesday. Timothy Herring, Jr., 24, was convicted of first degree murder and burglary for the November 2010 murders of Chicago police evidence technician Michael Flisk, 46, and retired CHA officer Stephen Peters, 44.

Herring was 19 and on parole at the time when both officers were gunned down at close range in a southeast side garage, prosecutors said. According to a news release from the Cook County State's Attorney's office, Peters owned a red Mustang that was parked inside the garage behind the home where his mother lived in the 8100 block of South Burnham.

Peters had called police on Nov. 26, 2010 to report the theft of car stereo equipment and other parts. Flisk was in full uniform and was taking photographs of the car and garage when Herring returned to the scene of the crime to look for more items to steal, prosecutors said.

Peters was standing in the alley when Herring approached and said he knew who committed the burglary but Peters told him it didn't matter because fingerprints had already been recovered from the scene, news reports said.

It was at that moment that Herring started walking away when he turned around and fired his weapon, prosecutors said.

Hearing the gunshots from inside her home, Peters' mother looked out the window when she saw her son lying in the alley bleeding and immediately called 911, As she called for emergency assistance, prosecutors said she heard two more gunshots and observed a male with a hood covering his head walking in the alley and pushing the garbage cans. Both men had sustained two fatal gunshot wounds to the head.