I’ll bet he was being bullied. s
I see the sarc tag, and know you are being sarcastic, but I am willing to bet some cash, that this will be the eventual "reason" for this mass attack. He was living in a white man's Christian, mean, oppressive world. Discriminated against constantly, and therefore it is completely reasonable for him to have gone on a terror attack, attempted killing spree.
This will be part of the "blame laying". Trust me. This is California.