The guy was already recognized as running off the rails, but nothing, NOTHING, was done in a timely and proactive manner.
This did not come out of the blue, and it had nothing to do with either the NRA or the enforcement of existing gun laws, in California or anywhere else.
This is a failure to adequate respond to increasingly erratic behavior, and that falls upon the local authorities, to whom this person was known and had a history, and to family and neighbors, who were well aware of the progression of the derangement that led to this fury and chaos.
Thousand Oaks is the third safest city in CA. They probably couldn’t think that something like that would happen there. Pride is a terrible sin.
One of the prime motivators for rampage murders like this is eternal fame from the Media.