Woodland Hills, California (CNN) -- In the aftermath of a deadly rampage in a Southern California college town, investigators want to know two things: Who was the man behind the gun, and why did he kill six people and wound 11 others?
Authorities have not released the identity of the man, who they say died from a gunshot wound to the head following a shootout with police during the rampage in Isla Vista, near the University of California, Santa Barbara.
But based on what police have told the family of 22-year-old Elliot Rodger, the parents believe he is the man behind the shootings, attorney Alan Shifman, the family spokesman, told reporters on Saturday.
As police piece together the gunman's path through the coastal college community, a neighborhood west of Santa Barbara, a portrait is emerging of a disturbed young man desperate for friends and companionship.
In a chilling YouTube video believed to have been posted by Rodger in the hours before the killings, he rants for nearly seven minutes against women who he says rejected him and popular kids who ignored him.
"Tomorrow is the day of retribution. The day in which I will have my revenge against humanity, against all of you," he said.
"For the past eight years of my life, ever since I hit puberty, I've been forced to endure an existence of loneliness, rejection and unfulfilled desires all because girls have never been attracted to me."
It's in that video, where he lays out a plan to kill blond sorority girls and states "now I will be a god compared to you."
Mass killing all too familiar in scenic college town of Isla Vista
The Santa Barbara County Sheriff's Office spokeswoman says investigators are analyzing writings and videos that suggest the rampage was "a premeditated mass murder," but stopped short of identifying whether Rodger's YouTube was one.
Rodger's family contacted police in the weeks before the rampage because they were concerned about his mental well-being after discovering social media posts about suicide and killing people, Shifman told reporters. Authorities, who interviewed Rodger, described him as "polite" and "kind," he said.
In a number of social media posts, Rodgers portrayed himself of a well-off young man who drove a black BMW Series 3 Coupe, traveled the world and attended college at Santa Barbara City College.
"I consider myself a sophisticated, polite gentleman, unlike most boys my age," according to a statement posted on "Elliot Rodger's Official Blog."
"... I enjoy hiking, exercising, watching sunsets, traveling, cars, fashion, going to nice restaurants, and going to parties."
CNN cannot confirm the authenticity of the social media posts.
Transcript of Elliot Rodger 'Retribution' video
By Rodger's own purported account on the blog, he claims to have been born in the United Kingdom before moving to the United States at the age of 5.
He was raised in the shadow of Hollywood, in the affluent Los Angeles suburb of Woodland Hills, by his father -- a commercial photographer and sometimes director -- and his stepmother, an actress who appeared alongside Matt Damon in "The Green Zone'' and Gerard Butler in "Playing for Keeps."
Pictures posted on Rodger's Facebook page show him with his father, Peter, on the red carpet at the premiere of the 2012 film "The Hunger Games."
Peter Rodger briefly worked as a second unit assistant director on the film, according to a spokeswoman with Lionsgate Entertainment, the company behind "The Hunger Games" movie franchise.
But it's also in these writings and videos posted on social media, where Rodger rails against life in Isla Vista.
"I have tried very hard to fit in with the social scene there, but I have ultimately been unable to do so. There are too many obnoxious people who have ruined my whole experience at that place," according to a statement posted on the blog.
