There were quite a few people in my old neighborhood who had mental health issues. BUT THEY WERE NEVER VIOLENT. There was one old dear who thought she was a nun, who was a bit of a trial to worshippers at the local Catholic church. But she was a peaceful nuisance. Most people with mental health problems aren't violent. Only a tiny minority are dangerous, and they are more so, because they have easy access to firearms.

You know it's a felony to own a ninja throwing star in California. But any nut can buy a gun.