A Coraopolis man who police said was using his vehicle as a weapon was shot and killed early yesterday in Moon by an Allegheny County police officer.

Gary Dennison, 64, was shot at 12:46 a.m. in the 100 block of South Patton Drive. County police Lt. Christopher Kearns said the officer, whose identity has not been released, "fired his weapon to prevent serious bodily injury or death to another county police officer."

According to police Superintendent Charles Moffatt, county officers tried to pull Mr. Dennison over for a traffic violation, but he did not say where. Mr. Dennison refused to stop, the superintendent said.

At some point, Superintendent Moffatt said, Mr. Dennison began using his older model Ford Thunderbird as a weapon, but he would not explain in what way.

"It's an odd situation," he said.

Police released few details about the shooting and said that the physical evidence from the scene -- a pleasant street of manicured lawns and well-kept homes -- was still being reviewed.

The Allegheny County district attorney's office will go over the circumstances of the shooting to determine if it was justifiable, Superintendent Moffatt said.

Mr. Dennison's daughter, Lara Sisler, said she was told by the Allegheny County medical examiner's office that her father was shot in the torso.

"They said he wouldn't stop the vehicle," she said, "so the police drew their weapons and shot him."

An employee of the medical examiner's office read a report to her that said police found a firearm in Mr. Dennison's vehicle, Ms. Sisler said. Her father, a retired employee of US Airways, had a license to carry the weapon, she said.

Ms. Sisler, 38, of Green Tree, complained that she was not contacted by county police until yesterday evening and learned of her father's death from a television newscast. Beaver police notified Mr. Dennison's ex-wife of his death. The two have been divorced for more than 20 years, Ms. Sisler said.

She spoke with her father Friday morning, and she said there didn't appear to be anything wrong.

"I talk to him every day," she said. Mr. Dennison had many friends, his daughter said, and enjoyed golfing, fishing, playing pool and bowling. He'd been retired for about eight years.

There are no criminal records listed for him in Allegheny, Beaver or Butler counties, and his daughter said she knew of no trouble with police.

Her father, a Vietnam veteran, had an inner ear problem that often resulted in dizziness and vertigo, Ms. Sisler said.

Lt. Kearns would not comment on the status of the officer who fired the shot that killed Mr. Dennison.

The medical examiner's office said its examination was not complete.

Copeland Funeral Home in Coraopolis is handling arrangements for Mr. Dennison.