The son of a state senator in the US stabbed his father in the head and chest before apparently killing himself with a gun, according to initial reports from police.

Authorities on Tuesday were still piecing together a motive and the circumstances that led up to the stabbing of Virginia state Senator Creigh Deeds.

"We're leaning towards it being an attempted murder/suicide," Virginia State Police spokeswoman Corrine Geller said.

Deeds' 24-year-old son, Gus, died at the home of a gunshot wound.

Geller said Creigh Deeds and his son were the only people at the home, and police were not looking for a suspect.

The senator was in fair condition at a hospital. He had previously been listed in critical.

After the stabbing, Deeds was able to walk away from his rural home to a nearby road and a cousin who was driving by happened to notice the senator, police said.

Mental health evaluation

Inside the senator's home, authorities found Gus Deeds with a gunshot wound.

Despite efforts by state troopers and first responders, he died there.

Gus Deeds is one of the senator's four adult children.

According to local paper the Richmond Times-Dispatch, Gus Deeds underwent a mental health evaluation on Monday at Bath Community Hospital, but was released because no psychiatric beds had been available.

He was studying music at the College of William and Mary, where he had been enrolled off and on since 2007, but withdrew last month, school spokesman Brian Whitson said.

The college said he had a strong academic record and did not say why he left.

During Deeds' bid for governor, his son took off a semester to join his father on the campaign trail.

"He needs me and I need him," Deeds told a reporter in the fall of 2009, about campaigning with Gus.

"I've got to go through this campaign process but that doesn't mean I've got to be completely separated from my family the whole time."