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.
Rodger opened fire on bystanders as he terrorized Isla Vista in his car and on foot in a killing spree that ended when he took his life 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 threatening YouTube video, a young man presumed by police to be Rodger bitterly complains of loneliness and rejection by women and lays out plans to kill those he believes spurned him.
"It's obviously the work of a madman," Sheriff Bill Brown told a news conference about the rampage, adding that Rodgers 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 where many college students live. At least 13 people were wounded, including eight who were shot.
Brown said his department had three times been in contact with Rodger prior to the killings, including once after a family member asked them to check on his welfare last month. Deputies interviewed Rodger but 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 deputies determined he did not meet the criteria to be held involuntarily on mental health grounds.
The son of assistant director Peter Rodger on the 2012 film "The Hunger Games," Elliot Rodger had previously gone to authorities to report a roommate had stolen some candles. Another time, he reported being the victim of an assault. Authorities said they later 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 family home in the Woodland Hills neighborhood of Los Angeles, reading from a prepared statement on behalf of the family.
"We are experiencing the most inconceivable pain and our hearts go out to everyone involved," he added.
The YouTube video police were studying shows a young man who identified himself as Elliot Rodger pouring out his hatred of women who have rejected him and "popular kids," and 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, since removed from YouTube as a violation of its policies, appeared to have been uploaded to YouTube on Friday night, shortly before the shooting. Brown said Rodger had also penned a 141-page manifesto, in addition to posting several disturbing videos.
Rodger's killing spree appeared to begin in his apartment in Isla Vista, where he repeatedly stabbed three men, killing them and 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 for at least a minute. But no one from the collegiate women's organization answered, Brown said.
He said that shortly afterward, witnesses reported seeing Rodger shoot three young women standing outside the sorority house. Two of those women, students Katherine Cooper, 22, and Veronica Weiss, 19, died.
Driving off to a nearby delicatessen, Rodger got out of his car, entered the deli and shot dead 20-year-old UCSB student Christopher Michael-Martinez, Brown said. Police responded and Rodger fled in his car.
He shot at pedestrians as he drove around Isla Vista, traded fire with police and struck bicyclists on two occasions before he crashed his car and 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, close to collapsing from emotion. "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, saying responsible gun owners should not be punished for mass shootings.
Robert Johnson, a 21-year-old UCSB student, said he first noticed trouble after a car drove past him at a busy Isla Vista intersection and he then heard "popping noises" that he originally mistook for firecrackers or the car backfiring.
"Then the sound came again, and by that point it had pulled up in front of a convenience store deli, and someone in the car was firing into a crowd of about eight, 10 people that were gathered in front of the store," he said.
"Everyone that was being fired upon, they all jumped and scrambled to run inside the store," he said.
The car had darkly tinted windows and the occupant was not visible, Johnson said.
College student Brad Martin told a UCSB student newspaper that his girlfriend was "absolutely hysterical" after being approached by the gunman with a weapon she initially was not sure was real.
"She said the next second he raised it up to her face ... and she turned around and started running," Martin told the Daily Nexus. "That's when she heard 'bang, bang, bang' right behind her as she was running."
The incident was the latest mass shooting in the United States, where schools, shopping malls and military bases have been scenes of such crimes.
In December 2012, 20 children and six adults were killed in a mass shooting at an elementary school in Connecticut, six months after a gunman killed 14 people in a Colorado movie theater.
The deadliest U.S. mass shooting in modern times was in 2007, when a student at Virginia Tech killed 32 people in a shooting spree.