A 22-year-old man killed six people before taking his own life in a rampage through a California college town shortly after he posted a threatening video railing against women, police said on Saturday.
Elliot Rodger, the son of a Hollywood director, stabbed three people to death in his apartment before gunning down three more victims on Friday night in the town of Isla Vista near the campus of the University of California at Santa Barbara (UCSB).
Rodger stalked Isla Vista in his car and on foot, firing on bystanders in a killing spree that ended when he killed himself after a shootout with sheriff's deputies, police said.
Authorities found three legally purchased semiautomatic guns, two Sig Sauers and a Glock, and more than 400 rounds of unspent ammunition in his car.
In a YouTube video a young man believed by police to be Rodger bitterly complained of loneliness and rejection by women and outlines his plan to kill those he believed spurned him.
"It's obviously the work of a madman," Sheriff Bill Brown told a news conference, adding that Rodger had been seen by a variety of health care professionals and that it was "very, very apparent he was severely mentally disturbed."
Witnesses reported seeing someone driving a black BMW through the streets and shooting at people in the beachside community which is home to many college students. At least 13 people were wounded, eight of whom were shot.
The Santa Barbara Cottage Hospital said on Saturday night that six victims were still being treated in its trauma unit.
Brown said his department had been in contact with Rodger three times prior to the killings, including once after a family member asked them to check on his welfare last month. Deputies who interviewed Rodger found him to be polite and courteous and took no further action, Brown said.
"He expressed to deputies he was having difficulties with his social life and would probably not be returning to school within the next year," Brown said, adding that Rodger was not thought to have met the criteria to be held involuntarily.
A crowd of about 5,000 people met at UCSB for a vigil on Saturday, filling Isla Verde's narrow streets before converging in silence on a local park.
The son of an assistant director on the 2012 film "The Hunger Games" Peter Rodger, he had previously complained to authorities about a roommate having stolen some candles. On another occasion he reported having been assaulted, but authorities said they suspected he may have been the aggressor.
"We offer our deepest, compassionate sympathy to the families involved in this terrible tragedy," lawyer Alan Shifman told reporters outside the Rodger family home in the Woodland Hills neighborhood of Los Angeles, reading from a statement.
"We are experiencing the most inconceivable pain and our hearts go out to everyone involved."
In the YouTube video a young man who identified himself as Elliot Rodger venting his hatred of women who had rejected him, as well as "popular kids", while threatening to kill people out of loneliness and sexual frustration.
"You girls have never been attracted to me. I don't know why you girls aren't attracted to me. But I will punish you all for it. It's an injustice, a crime," he said in the video, his speech punctuated by bursts of laughter.
The clip, later removed from YouTube as a violation of its policies, appeared to have been uploaded to the site on Friday night shortly before the shooting. Brown said Rodger had also penned a 141-page manifesto and posted other disturbing videos.
The killing spree appeared to begin in Rodger's Isla Verde apartment, where he repeatedly stabbed three men to death, leaving behind what Brown described as a horrifying crime scene.
He then made his way to a nearby sorority house, whose members heard loud and aggressive knocking on the door but did not respond, Brown said.
Shortly afterward witnesses reported seeing Rodger shoot three young women standing outside the sorority house, including students Katherine Cooper, 22, and Veronica Weiss, 19, who died.
Driving to a nearby delicatessen, Rodger entered and shot dead 20-year-old UCSB student Christopher Michael-Martinez before fleeing in his car.
Alyssa Adams, 20, also a UCSB student, said Rodger shot up a patio at the pizza restaurant where she works.
"Everyone ducked and covered. People were running from outside" to get into the restaurant, Adams said.
As he drove, Rodger shot at pedestrians, traded fire with police and struck two bicyclists before crashing. Officers found him with an apparently self-inflicted gunshot wound to the head, Brown said.
Richard Martinez told reporters that his son Christopher was an English major who wanted to go to law school.
"Why did Chris die? Chris died because of craven, irresponsible politicians and the NRA," Martinez told reporters outside the Santa Barbara County Sheriff's Office, appearing on the verge of collapse. "They talk about gun rights, what about Chris' right to live? When will this insanity stop?"
The National Rifle Association, or NRA, supports the right to own and carry firearms.
'Sounded like fireworks'
Trent Anderson, 21, a student at Santa Barbara City College, said in a phone interview that he and a friend had gone to the deli then walked a short distance when they heard shots.
"It sounded like six to eight shots," Anderson said. "He just blasted it up. He unloaded the clips so fast it sounded like fireworks."
The incident follows U.S. mass shooting at schools, shopping malls and military bases.
In April, a soldier killed three people and wounded 16 before killing himself in a shooting rampage at Fort Hood Army base in Texas.
The deadliest U.S. mass shooting in modern times was in 2007 when a student at Virginia Tech killed 32 people.