A 137-page memoir details the jealousy and anger Elliot Rodger felt before he killed six people in a furious rampage near the University of California, Santa Barbara.
"All I ever wanted was to fit in and live a happy life amongst humanity, but I was cast out and rejected, forced to endure an existence of loneliness and insignificance, all because the females of the human species were incapable of seeing the value in me," he wrote in the document, titled "My Twisted World."
Police identified Rodger, 22, as the shooter, a man who videotaped his rage over his rejection by women and vowed "retribution" just hours before the killing began. He was also identified as the killer by a lawyer for his father Peter Rodger, who was the assistant director for one of the “Hunger Games” films.
Read: Father of Santa Barbara Victim Sobs and Rails Against Son’s Death
In the manifesto, Rodger described police visiting him after he uploaded several videos to YouTube. A member of his family asked police to check on him because of alarm over his behavior and videos.
"As soon as I saw those cops, the biggest fear I had ever felt in my life overcame me," he wrote. "I had the striking and devastating fear that someone had somehow discovered what I was planning to do, and reported me for it."
In a YouTube video titled "Elliot Rodger's Retribution" that he posted before the killing spree began, Rodger sat in the driver's seat of a car as he promised "retribution" and discussed his "loneliness, rejection and unfulfilled desires."
"Girls gave their affection and sex and love to other men but never to me," he said in the video, which he added would be his last.
Rodger also expressed the jealousy he felt toward his younger brother, who he described as socially savvy.
"It is very unfair how some boys are able to live such pleasurable lives while I never had any taste of it, and now it has been confirmed to me that my little brother will become one of them," Rodger wrote in the manifesto. "He will become a popular kid who gets all the girls. Girls will love him. He will become one of my enemies."
Santa Barbara County Sheriff Bill Brown called the manifesto "rambling."
Friend Calls Rodger "a Really Lonely Guy"
Andi Chan, a friend of Rodger for two and a half years, described him as a "really lonely guy" who was often depressing to be around.
"Me and my friends tried to help him," said Chan. "He doesn't like to talk or hang out."
Chan said Rodger often talked about finding a girlfriend, something he echoed in videos posted to YouTube and the manifesto.
"He asked why the world is unfair to him. 'I'm a good looking guy. Why do girls like ugly, fat guys?'" said Chan. "I told him appearance wasn't everything."
Chan said after they saw the 2012 film "Chronicle," Rodger said he wanted to "dominate the world." In the film, three high school students gain superpowers and one character - who's bullied, shy and lonely - eventually uses them in a robbery and in an attempt to kill his father. He dies at the end of the film, killed by one of the other students.
"We all thought he was insane but we were used to it," said Chan. "Maybe in his mind he really wanted to do that."
Chan said he realized Rodger was involved in the shooting when he saw a photo of his BMW.
"I started to search for the shooter's name, then I saw stuff on Facebook," he said. "I was shocked and disappointed. No matter how angry you get, you are - you can't kill people."