What to make of a disturbed young man who rants about killing women in revenge for them not having sex with him, who then murders two, as well as four men?

There's not much to like about Elliot Rodger - entitled, self-pitying, vain, insecure, histrionic, materialistic, racist, boastful and ungrateful - yet it's difficult for any of us to judge how many of these attributes arose from mental health issues or were simply the result of a nasty little mind. Our knowledge of him is incomplete.

The six Isla Vista massacre victims, from top left: Christopher Michaels-Martinez, Veronika Weiss, Katie Cooper, Cheng-Yuan Hong, George Chen, Weihan Wang.

What seems indisputable is he was an incredibly lonely young man, a virgin who'd never kissed a woman and didn't have a single male friend in the world. Reading his"manifesto" and watching his videos, it seems pretty clear Rodger hated everybody - women because they'd rejected him and men because they'd led the sexually active lives he'd not.

He disliked blacks, Indians and Asians - despite being Eurasian himself - and at least a few of his hang ups stemmed from this. He attached disproportionate importance to being "half-white", reasoning Asians were of less value in the world in which he lived.