report, the young man's own family and a social worker who knew him had raised alarms. Tonight here what could those videos reveal? Gio Benitez on that part of the story. Reporter: It appears Elliott... See More
report, the young man's own family and a social worker who knew him had raised alarms. Tonight here what could those videos reveal? Gio Benitez on that part of the story. Reporter: It appears Elliott Rodger used his youtube channel as a manifesto. My life is so lonely and mundane. Reporter: The videos were posted just this month and many show roger exploring beautiful southern California. A beautiful environment is the darkest hell if you have to experience it all alone. Reporter: Take a look at this. One video has this description. I temporarily took all of my vlogs down due to the alarm it caused with some people in my family. That diagnosis of aspergers, experts say it does not trigger violence. There's obviously something else going on. Reporter: We brought in Dr. Robi Ludwig to look at these videos with us. This is Elliott at a golf course. It's one of the few places where I can come and truly have a sense of escape. He says there was something he was trying to escape. Escape rejection, escape this idea that he's not good enough, that he's inferior. All the people rejecting him are enemies. This is Elliott watching a couple there on the beach. They're kissing right now. It's torture for me to watch but I have to do this. I have to film this. He's forcing himself to watch this so that he can build up the courage he needs to exact revenge. And this is a video titled "Life is so unfair because girls don't want me." I'm such a magnificent guy. I'm beautiful. You can't deny that. He's calling himself beautiful. Yeah. You can't deny that. Wonder if there's a mania there. He's a beautiful guy, he's a fabulous guy. Well, why isn't he in a loving relationship? That's where he goes into a blame mode. Reporter: So now those familiar questions, could this carnage have been prevented and did law enforcement do enough? Could they have been maybe more proactive in talking to mental health folks, perhaps. But there may not have been enough there to actually involuntarily commit him. Reporter: No one can know for sure but as Dr. Ludwig says, this is not someone who ever wondered what should I do different. Instead he always seemed to blame everyone else. A lot of people looking at those videos posted on youtube. Thank you. We'll continue to follow this throughout the evening and much more on the deadly rampage first thing in the morning right here on "Good morning America" and "This week." We turn next to the severe
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