William O'Brien killed in possible road rage incident

Police in Fairfax are investigating a homicide they believe was the result of road rage.

On this perfect spring day, Bill Ryal probably expected to see William O'Brien doing what he always did.

"Nice gentleman. Used to walk his dog up and down the street every day," said Ryal.

He can't believe his neighbor's death could have stemmed from an incident road rage.

"You see it around but never think it will escalate to that point," Ryal added.

Police believe some sort of traffic incident happened near the intersection of Pickett Road and Main Street on April 16 around 11 a.m.

"We're still trying to find out the initial reason for this," said Fairfax Police Department Sgt. Kyle Penman.

Authorities say after the incident, O'Brien, 63, got out of his car in the nearby Best Buy parking lot, where he was confronted by 57-year-old Librado Cena. According to police, Cena his O'Brien in the head and took off. O'Brien, meanwhile, continued with his errands. But when he got home, he didn't feel okay and was taken to the hospital.

O'Brien died 10 days later. His death was a direct result of the assault, the medical examiner ruled.

Cena was tracked down two days after the alleged assault.

"An alert patrol supervisor saw the vehicle, initiated a traffic stop, talked to him and brought him back to the station...," Penman explained.

Cena was initially charged with aggravated malicious wounding, but those charges may change in response to O'Brien's death.

Cena's neighbor, Vicky McLaine said she would never expect Cena to be involved in something like this.

"I feel very badly for the family suffering from this loss," she added.

Cena is currently out on bond and will appear in court in July.