I read the entire manifesto. He writes exactly like a friend of mine who is high functioning but with pretty severe Aspergers. In his manifesto he references the regional center several times.
Regional Centers in CA only serve people with developmental disabilities (autism, aspergers, mental retardation, etc). It is NOT easy to access their services as the need is enormous and funding is...not. In order to even be taken on as a client you have to undergo evaluation after evaluation (most of the time these are done in early childhood as RCs only take people who's disability is identified before age 18) and it takes a lot of dedication and advocating on the parent's part. They do not fund people who are "only" mentally ill, they do not fund people who are brain damaged due to an accident. Certainly a lot of their clients are dual diagnosed (both DD and MI) but in order to have an established case with an RC, it has to be because of a DD (developmental disability). And it has to have occurred before the age of 18. I am intimately aware of this system in CA and knowing it as well as I do, his references to it and receiving services from them indicate he was identified early on and that his parents sought help.
Not that this hasn't been stated in the media, but people here seem to be questioning whether or not his parents did "enough" and I thought I would throw in that info.
People who say he's "faking it" or "fooling" his parents, I assure you, he would not have received services if it was not determined that he did have a fairly significant developmental delay. That isn't to say that he doesn't have free will, that he isn't evil, that he isn't also most likely mentally ill and a sociopath, but he is most definitely not masquerading as a person with issues.