Authorities investigating the slaying of a northern Illinois police officer say they've recovered a new piece of "significant" evidence from the crime scene.

Lake County Sheriff's Office detective Christopher Covelli says evidence technicians returning to the scene of Tuesday's shooting in the village of Fox Lake made the discovery Friday afternoon.

He refused to reveal what it was, citing the ongoing investigation.

Police Lt. Charles Joseph Gliniewicz was slain Tuesday while pursuing three suspicious men on foot.

Covelli also told The Associated Press Saturday that technicians piecing together several videos have told investigators some of the images line up with the description Gliniewicz gave dispatchers of the men.

Covelli says that puts investigators closer to identifying potential suspects.

Residents and businesses have come forward with some of the videos.