The shooter remains at large as police continue to look for more clues.
"Over the past two days, dive teams have searched the frozen ponds and streams in the area for the purpose of finding any potential evidence pertaining to this investigation. Officers have conducted grid searches of roadsides and interstates," said Cmdr. Rick Bruno of the Tinley Park Police Department.
Police are also following up on tips. They have gotten more than 200 calls to their 24-hour hot-line.
