Bardstown Police Dept. Bardstown, Ky., police officer Jason Ellis was killed in an ambush on Saturday. Police said they have no suspects.

Kentucky police said they are hunting for clues in the "premeditated" murder of a K-9 officer who was lured out of his cruiser and blasted with a shotgun.

Investigators believe the killer may have planted road debris on the Bluegrass Parkway and then lay in wait for someone to stop and pick it up.

They are not sure if Bardstown Police Officer Jason Ellis was the intended target of the Saturday night ambush or if the shooter planned to fire randomly on the first person who stopped.

“Someone planned this, and someone planned to shoot someone at that spot and at that time,” Kentucky State Police Master Trooper Norman Chaffins said at a Sunday briefing.

Police asked for anyone who had seen anything unusual in the area in recent days to get in touch, but there are no strong leads.

"We've received some information but not a tremendous amount," Lt. Jeremy Thompson said Monday.

Ellis, 33, did not have a partner with him and was likely on his way home when he was killed on the exit ramp about 40 miles southeast of Louisville, police said.

Passersby called 911 and reported a car crash, but the trooper who responded "quickly noticed that this was no traffic accident," Chaffins said.

"Officer Ellis was shot multiple times and was ambushed as he exited his cruiser," Chaffins added. "Officer Ellis never fired a shot from his service weapon. It was still holstered."

He said there are no suspects and raised the possibility that more than one person may have been involved. Police did not provide a description of the debris that was left on the ramp.

A funeral for Ellis, a married father of two who had been on the police force for seven years, is scheduled for Thursday.