Vehicle skid marks leading to the point where a 62-year-old man was found unconscious and fatally injured on a northwest Santa Rosa street last week focused the investigation on the likelihood of a hit-and-run crash, police said Friday.

Mike Nunes was found on the side of Peterson Lane shortly after 9 p.m. Friday, Jan. 4 with significant head trauma, police said. He died early Wednesday at Santa Rosa Memorial Hospital.

In the meantime, authorities had said it was not clear how Nunes was injured, and his case was being investigated by the police department's violent crimes team, jointly with traffic investigations.

Family members said they feared Nunes had been assaulted, because his injuries were largely above his shoulders.

But the case was transferred to the traffic investigations unit earlier this week, and Sgt. Mike Numainville said Friday that skid marks at the scene led right up to Nunes' body, "indicating he was struck by a vehicle."

Police were never able to interview Nunes because of his injuries, Numainville said.

Nunes reportedly worked at Chevron gas station in north Santa Rosa and lived in a rented room on Partridge Court, around the corner from where he was found injured on Peterson Lane north of Guerneville Road.

Family members surmise he was walking to a nearby Rotten Robbie service station when he was hurt.

A witness reported seeing a smaller white car with a loud exhaust system in the area, though there was no confirmation the vehicle was involved, police said. It appeared two men were in the car.

Investigators otherwise have no leads.

"We're hoping somebody will come forward, but we don't have any more information," Numainville said. "Hopefully we can get some more but right now we don't have anything."

Anyone with information about the case can call police at (707) 543-3600.