A California gunman stabbed three people to death at his apartment before getting in his car to kill more.
The three people in the apartment were among the six left dead on Friday night (local time) during the shootings near the campus of the University of California, Santa Barbara.
The killing spree appeared to be driven by Elliot Rodger's twisted desire to get revenge on the girls who had rejected him since puberty. After crashing his car, the 22-year-old shot himself in the head.
Sheriff Bill Brown called it a "chaotic, rapidly unfolding convoluted incident" that involved multiple crime scenes. Seven people remained hospitalised with serious injuries.
Rodger is the son of Hollywood director Peter Rodger, one of the assistant directors on The Hunger Games.
Police described how the gunman went from one location to another, opening fire on random people and exchanging gunfire with law enforcement, before he crashed his BMW. Brown said the gunman had three legally purchased guns and more than 400 rounds of unspent ammunition in his car.
The gunfire continued for 10 minutes as the gunman made his way through the beach community in a rampage that mirrored threats made on a YouTube video posted the same night, authorities said.
Investigators were analyzing the video in which a young man who identifies himself as Elliot Rodger sits in a car and looks at the camera, laughing often, and says he is going to take his revenge against humanity.
"This is my last video, it all has to come to this. Tomorrow I will have my revenge against humanity, against all of you."
As he sits in his car recording the video, he talks about his loneliness, alienation and rage, saying, "girls gave their affection and sex and love to other men but never to me".
"Girls, all I've ever wanted was to love you and to be loved by you. I've wanted sex. I've wanted love, affection, adoration. You think I'm unworthy of it. That's a crime that can never be forgiven. If I can't have you girls, I will destroy you.
"I'll take great pleasure in slaughtering all of you. You will finally see that I am in truth the superior one, the true alpha male."
He says that although he is 22 he has never even been kissed or had sex.
"It's obviously the work of a madman," Brown said.
Rodger had also apparently left a printed manifesto describing his anger and alienation.
Channel 3 in Santa Barbara also obtained a copy of the 140-page document, which read in part: "On the day before the Day of Retribution, I will start the First Phase of my vengeance: Silently killing as many people as I can around Isla Vista by luring them into my apartment through some form of trickery."
Earlier on Saturday, Alan Shifman - a lawyer who represents Peter Rodger - issued a statement saying his client believed his son, Elliot Rodger, was the shooter. It was unclear how the son would have obtained a gun. The family is staunchly against guns, he added.
"The Rodger family offers their deepest compassion and sympathy to the families involved in this terrible tragedy. We are experiencing the most inconceivable pain, and our hearts go out to everybody involved," Shifman said.
Richard Martinez said his son Christopher Martinez, 20, was killed. He blamed politicians and gun-rights proponents. "When will this insanity stop? ... Too many have died. We should say to ourselves, 'not one more'," he said.
Alexander Mattera, 23, said his friend Chris Johnson was walking out of a comedy show when he was shot and stumbled into a nearby house.
"He walked into these random guys' house bleeding," he said.
Mattera was sitting at a bonfire with friends when at least one gunshot whizzed overhead. The friends ran for cover.
"We heard so many gunshots. It was unbelievable. I thought they were firecrackers. There had to have been at least like two guns. There were a lot of shots," he said.
The gunman got into two gun battles before crashing his black BMW into a parked car.
Describing the shootings as "premeditated mass murder", Brown said a YouTube video posted on Friday that shows a young man describing plans to shoot women appears to be connected to the attack.
The young man describes loneliness and frustration because "girls have never been attracted to me", and says, at age 22, he is still a virgin. The video, which is almost seven minutes long, appears scripted.
Shifman, the attorney for the Rodger family, said the family called police several weeks ago after being alarmed by YouTube videos "regarding suicide and the killing of people" that Elliot Rodger had been posting.
Police interviewed Elliot Rodger and found him to be a "perfectly polite, kind and wonderful human", he added. Police did not find a history of guns, but did say Rodger "didn't have a lot of friends", had trouble making friends and didn't have any girlfriends.
Blood was still visible on the street on Saturday. The wrecked BMW remained, its windshield smashed in and its driver's door wide open.
The community has experienced other tragedies in the past.
In 2001, the son of Ally McBeal TV director Daniel Attias ran down four pedestrians with his car on a crowded Isla Vista street. Witnesses testified that part-time college student David Attias got of the car and shouted: "I am the angel of death."
David Attias was ruled insane after he was convicted of second-degree murder and is locked up in a state mental hospital.