A picture of Elliot Rodger is displayed during a news conference by Santa Barbara County Sheriff Bill Brown (not shown) at Sheriff headquarters in Santa Barbara, California May 24, 2014. Brown confirmed that Elliot Oliver Robertson Rodger is the suspect in a mass shooting that left 6 people dead and 13 injured in the college neighborhood of Isla Vista near UC Santa Barbara. [Photo/Agencies]

SANTA BARBARA, Calif. -- A 22-year-old gunman killed six people before taking his own life in a rampage across 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.

7 dead, including gunman, in California shooting

Rodger opened fire on bystanders from 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 ammunition in his car.

At least 13 people were wounded, including eight who were shot.

In a 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, adding the community college student 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.

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.

WROTE MANIFESTO

A 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, 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 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 outside the sorority house. Katherine Cooper, 22, and Veronica Weiss, 19, died.

Driving off to a nearby delicatessen, Rodger 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, traded fire with police and struck two bicyclists 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.

'TRIGGER HAPPY'

Trent Anderson, 21, a student at Santa Barbara City College, said in a phone interview that he and a friend went to the deli to get food and then walked away a short distance when they heard shots fired.

"It sounded like six to eight shots," Anderson said. "He just blasted it up. He unloaded the clips so fast it sounded like fireworks, he was trigger-happy."

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 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.

Following the latest attack, a crowd of about 5,000 people, most of them holding candles, met at UCSB for a vigil and then filled the narrow streets of Isla Vista as they converged on a park. The largely college-age crowd walked in a silence broken only by their footsteps on the pavement. (Additional reporting by Alex Dobuzinskis, Peter Cooney, Jonathan Allen, Jonathan Alcorn, Kevin Murphy, Ellen Wulfhorst; Writing by Cynthia Johnston; Editing by Frances Kerry, Bill Trott and Lisa Shumaker)