Actually, it's a very complex problem.
It involves a Mental health system disabled by the ACLU and the cost of medical care, it involves the revolving doors we call a Correctional System and it's methods of handling the mentally ill or handicapped, it involves the teaching of children that games involving gory and detailed killing as entertainment from the time they're 6-7 years old that isn't any better than letting them watch pornography from the same age, and lastly, hell yes, it involves guns . .
But I grew up hunting and shooting, but have never had the slightest inclination to shoot up a theatre, a school or my work place, so I'm either "normal" or "not crazy enough" . . dunno which . .
As for owning an "Assault Rifle", I dunno why anyone needs one, until they get one . . Years ago, I built a house out on the high prairie, West of the city. There were coyotes and all the other wildlife you encounter when you live in the boondocks and while I had several guns that would do the job, I suppose, I decided I needed a "Ranch Rifle" to carry in my pickup . . I had a 94 Winchester but it was getting to be worth way too much to carry around in a truck and possibly get stolen. so, I visited a buddy who had a Gun Store . . He sold me the first Stainless Mini 14 I'd ever seen, for $169 . . and threw in four 20 round mags . . Voila! I owned an "Assault Rifle" . . wish I had it now. It's worth about $900 . .
The boss has an AR style in .308, mossy oak camo with a Lepould variable on it, shot 2 elk with it last November . . Sumbitch is deadly accurate at 300 yds . . Probably as good or better than any of the varmit guns I've had over the years . .