Timeline Leading To Death Of Fox Lake Officer Charles Joseph Gliniewicz

CHICAGO (CBS) -- As the intensive investigation into the fatal shooting of a veteran Fox Lake police officer continues, authorities released the timeline surrounding Tuesday morning's altercation with three suspects.

7:52 a.m. Lt. Charles Joseph Gliniewicz calls dispatch, reports three men acting "suspicious."
7:55 a.m. Gliniewicz calls in for backup. (At some point, the three suspects ran into a swamp.)
8:01 a.m. Additional officers arrive.
8:09 a.m. The officers find Gliniewicz's body.

An autopsy found Gliniewicz suffered two gunshot wounds.

Investigators have not released any descriptions of the suspects, only that they are two white males and a black man.

George Filenko, commander of the Lake County Major Crimes Task Force, said the investigation is continuing, with detectives gathering evidence and following up on leads, which includes more than 100 tips. The U.S. Marshal, FBI and ATF are also assisting local authorities.

At a news midday news conference, Filenko said that some surveillance tape had been collected and investigators were seeking more, but he didn't know if there was a dash camera in the officer's car. He also said investigators believe the suspects left the crime scene on foot.