A motorist driving west on Pennsylvania Avenue on Capitol Hill during the evening rush hour yesterday was shot in the head by a pedestrian, causing his car to careen across several lanes of traffic and two grassy medians before smashing into three cars, police said.

Police said the victim, whose name was not released, was in grave condition at D.C. General Hospital last night.

"It looks like a random shooting," said Lt. Tommy Musgrove, a homicide investigator. "From what we were told, the guy just started shooting."

Authorities said the assailant fled on foot, and police had no suspects last night.

A resident of the 1000 block of E Street SE, which intersects Pennsylvania Avenue near the scene of the shooting, said he heard gunshots as he was leaving his house about 6 p.m.

The man said he then saw a car skidding diagonally across Pennsylvania Avenue and over two median strips toward his truck, which was parked on E Street.

"It hit a car on the north side {of E Street}, spun off another car and stopped against my truck," the man said. He said that after liquid began gushing from the car, he pulled the shooting victim out of the driver's seat because he thought the car might explode.

The victim was unconscious and bleeding heavily from the back of the head, the resident said.

He and others who live in the area said violent crime is rare in their neighborhood, and that they were shaken by the incident. "It's unnerving any time this happens in your front yard," the man said.

"I've lived on this street 16 years, and this is the first time anything like this has happened," another resident said.