Elliot Rodger is Isla Vista drive-by killer - US police

US police have confirmed that a man who killed six people in a rampage in California was 22-year-old Elliot Rodger.

The student was the son of Hollywood filmmaker Peter Rodger, who was assistant director on The Hunger Games.

At a news conference, police said Elliot Rodger had stabbed three male room-mates to death at his apartment.

He later went on a rampage through Isla Vista in a black BMW, shooting at people at random.

After exchanging gunfire with police, Rodger was found dead inside his crashed vehicle with a gunshot wound to the head, police said.

Santa Barbara County Sheriff Bill Brown said Rodger apparently killed himself during a shoot-out with police officers.

At a press conference, he called it a "chaotic, rapidly unfolding convoluted incident" that involved multiple crime scenes.

Investigators are analysing a YouTube video in which a young man who identifies himself as Elliot Rodger sits in a car and says he is going to take his revenge against humanity.

In a so-called manifesto published online, Rodger said he was born in London and spent the first five years of his life in Sussex.

"This was a time of discovery, excitement, and fun. I had just entered this new world, and I knew nothing of the pain it would bring me later on," he wrote.

Sheriff Brown said that after leaving his apartment, Rodger had gone to a sorority house, which houses female students, and hammered loudly on the door.

They did not open the door but Rodger had then shot three women in the street, killing two of them, Sheriff Brown said.

Three victims were found at the apartment complex where Elliot Rodger lived

In a chilling video, Elliot Rodger railed against those he blamed for his isolation

Rodger then drove his car through the beachside community - which is near the University of California-Santa Barbara campus - targeting people at random, and the sixth victim was shot dead in a delicatessen.

Seven other people were wounded.

Sheriff Brown said it was "very apparent" that the gunman was "severely mentally disturbed", adding: "It's obviously the work of a madman."

He said authorities had recovered three semi-automatic handguns after Friday's shooting.

All the weapons were bought legally and were registered to Rodger, he said.

'Had trouble making friends'

Earlier, Peter Rodger's lawyer, Alan Shifman, said that the "family believes the child was the perpetrator".

He said Mr Rodger's son had been "diagnosed at an earlier age of being a highly functional Asperger Syndrome child", had trouble making friends and had been receiving professional help.

Asperger syndrome is a form of autism - a condition which affects how people make sense of the world, and interact with other people.

Mr Shifman added that the family had contacted police about "recent posts on YouTube" by Elliot "regarding suicide and the killing of people".

The family is "devastated" and co-operating with police, he said.

"We offer our deepest, compassionate sympathy to the families involved in this terrible tragedy," Mr Shifman told reporters outside the family home in Los Angeles,

Ricardo Martinez, whose 20-year-old son Christopher was one of the victims, spoke of his grief.

"When will this insanity stop? Too many have died. We should say to ourselves 'Not one more'," he said.

The University of California-Santa Barbara said it was "shocked and saddened'' by the shootings and confirmed that several of its students had been taken to hospital.