Federal agents have joined state police in their investigation into a fatal road rage incident on a Franklin County highway on Saturday.

Timothy Davison, 28, was driving home to Maine after visiting family in Florida when he was fatally shot after his SUV was rammed off Interstate 81 north of the Maryland line, according to state police.

Agents from the FBI's Harrisburg field office are assisting police in tracking down whoever shot Davison, police said in a news release issued Sunday.

The attack appears to have been random, but investigators are looking into whether it's related to a road-rage incident in which someone in a pickup truck fired a gun at another driver in Monaghan Township on Friday, police said.

No one was injured in that incident.

What happened: Davison called 911 from I-81 near Maryland early Saturday to say someone in a pickup truck was firing on him.

Police say Davison was then forced into a median before the assailant approached and fired several rounds at him.

Police say the shooting occurred in the southbound lanes in Antrim Township, about 10 miles north of Hagerstown, Md.

They say Davison, who was from Poland, Maine, died at York Hospital following the 2:10 a.m. attack.

An autopsy is scheduled for Monday.

Search: Police continue to search for the pickup truck believed to have been involved in the incident.

The smaller-style pickup truck, possibly a Ford Ranger, was driven by the suspect in the shooting. Police said the truck should have damage to the driver's side, in particular to the door and front quarter panel.

There may also be silver paint that transferred from Davison's 2001 Mitsubishi Montero SUV when it was rammed by the pickup truck, police said.

Police are asking for anyone with information, even if it's minor, to call state police at Chambersburg at (717) 264-5161.

Police are also asking collision and auto body shops to contact police if a pickup truck matching the description is brought in for repairs.