A Hollywood film-maker believes his son carried out drive-by shootings that killed six people in California late on Friday, a family lawyer says.
Peter Rodger, who was a director on The Hunger Games, thinks the attacker was his 22-year-old son Elliot, the statement said.
The gunman died of bullet wounds after going on a rampage near Santa Barbara.
Police are investigating a video in which a man complains of rejection by women, threatening revenge.
Authorities have not confirmed the identity of the gunman, or that of the young man seen in the YouTube video.
But Peter Rodger's lawyer, Alan Shifman, said on Saturday that the "family believes the child was the perpetrator".
He said the son had Asperger's syndrome, had trouble making friends and had been receiving professional help.
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.
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.
Santa Barbara County Sheriff Bill Brown told reporters on Friday that police were treating the incident as "premeditated mass murder".
It occurred in the area of Isla Vista, near the University of California-Santa Barbara campus.
Witnesses described seeing a black BMW speeding through the streets, with shots being fired at people.
Police say they were alerted around 21:30 on Friday (04:30 GMT on Saturday). Six minutes later, the suspect and responding officers exchanged gunfire.
The suspect fled. But after a second exchange of fire with police, he eventually crashed into a parked vehicle.
He was found dead in his car with a bullet wound to the head. although police say it is not yet clear whether the wound was self-inflicted.
A semi-automatic handgun was recovered from the vehicle.
Seven other people are in hospital, and being treated for bullet wounds.
The University of California-Santa Barbara said was "shocked and saddened'' by the shootings and that several of its students had been taken to hospital.
Santa Barbara shootings timeline, 23 May
21:27 local time: Shootings begin
21:33: Police exchange fire with gunman, who flees in his vehicle
Seconds later: More police exchange fire. Car crashes in Del Playa Drive, alleged gunman found dead