It's been one year since police began searching for the suspect who shot and killed a driver along I-81 North, in Franklin County.
The victim's mother is working with police to solve the apparent road rage homicide.
Theresa Allocca, of Poland Spring, Maine, says, "It's been really difficult. It's like something's always missing."
Allocca lost her son, Timothy "Asti" Davison a year ago this week.
She says, "It's been a struggle of adjustment we're just taking it day by day."
The person who chased and shot Asti to death along I-81 North near the Pennsylvania Maryland line remains at large.
Police say it happened on Saturday, January 4th, at around 2 a.m.
Davison called 911 and said he was being chased by another driver who was shooting at him. Police say the unknown suspect rammed his Ford Ranger pick-up truck into Davison's car. Then he got out of his truck and fired several shots at him.
Police have investigated hundreds of tips that have come through places like Crime Stoppers. They say they evidence collected has been sent to the FBI lab. They say they won't stop their investigation until they arrest Davison's killer.
Trooper Rob Hicks says, "Even though you haven't been hearing about the case, we've never stopped working. We continue to do so and we want people to know we still are seeking tips."
Allocca says, "Obviously someone knows something, whoever the person who did it and feels remorse, and comes forward that would be great."
The family is offering a $22,000 reward for anyone who can help police arrest the person who murdered Asti. "WANTED" signs are posted at welcome centers throughout Virginia, Maryland and Pennsylvania. For more information contact the PA Crime Stoppers at 1-800-4PA Tips. Or contact Asti's family at Justiceforasti.com