Updated

EXCLUSIVE: Kentucky investigators probing the murder of a police officer on a state highway last May plan to contact Pennsylvania authorities to see whether there is a connection to Saturday's road-rage killing there, an official told FoxNews.com.

"We're going to give them a call to see what we can find out," said Kentucky State Trooper Jeff Gregory, public information officer for the Kentucky State Police, which has been stymied for more than seven months since the murder of Jason Ellis, a Bardstown, Ky., cop shot and killed along a state highway May 25 after leaving his car to remove debris from the road.

Ellis, 33, was driving home at 2:53 a.m. when he stopped along Exit 34, a ramp off the Blue Grass Parkway in Nelson County. When Ellis began removing debris from the roadway, he was shot multiple times. Authorities said Ellis' vehicle had a dash-cam, but it was not on at the time of the shooting. The coroner said Ellis was killed with a 12-gauge shotgun.

The roadside killing bears some similarities to Saturday's murder of Timothy Davison, 28, of Poland, Maine. Davison was making the 1,400-mile trip home after spending the holidays with family members in Orlando, Fla., when he was shot to death early Saturday by an unknown person along I-81 in Pennsylvania in what authorities are calling a random and vicious road rage attack.

According to investigators, Davison made a call to 911 while driving through Maryland to report that a vehicle was tailgating him at around 2 a.m. Saturday. He lost contact with a Maryland 911 dispatcher as he crossed into Pennsylvania, then called back to say he was being shot at, according to police.

The suspect then rammed his pickup truck into Davison's SUV, forcing him off the road into a snow bank. The driver then got out of his vehicle and shot "a couple rounds into the car, striking and killing [Davison]," according to Pennsylvania State Trooper Robert Hicks.

Pennsylvania State Police, who are working with the FBI and police in neighboring states, are pleading with the public for help nabbing the pickup truck driver believed to have gunned down Davison. Trooper Adam Reed of the Pennsylvania State Police told FoxNews.com that authorities combed the crime scene again yesterday, hoping the melting snow might reveal additional evidence.

No suspects have been identified in either killing. State police in Pennsylvania also are investigating a connection between Davison's murder and a shooting that occurred Friday involving a pickup truck in Monaghan Township, Pa., about 30 miles away from the highway shooting, police said.

"The acts committed against Mr. Davison were random only to the point of his initial encounter with his assailant," the Pennsylvania State Police said in a statement earlier this week. "Beyond that, the acts against him were very deliberate, calculated and violent. With that said, the potential for additional incidents of similar nature is anticipated due to the violent nature of this incident."

"It is our belief that someone in the tri-state area knows who is or may be responsible for this homicide," the statement said.

"Both investigations will be treated as being related until conclusive evidence proves otherwise," police added, referring to Davison's murder and the case in Monaghan Township, Pa.

It was not known if there were any witnesses or if Davison had been able to provide a license plate number to police when he called 911. Police said the suspect fled south, which would have been back toward Maryland.

Although there is a state Department of Transportation traffic camera mounted along Interstate 81 near where the victim’s vehicle came to rest, the footage was of little use to police, Hicks said.

Anyone with information about the Pennsylvania shootings is urged to contact PA Crime Stoppers at 1-800-4PA-TIPS (800-472-8477). Police said a cash reward may be given for information leading to an arrest.