I want to know how the shooter got the guns. See, I hear a lot of flailing — a lot of assumptions.

There’s the mental health issue for example. To which I have to ask: if the weapons belonged to the shooter’s parent what good do mental health restrictions for ownership make?

Quantity? One rifle and two pistols. We don’t know anything yet about the weapon owners (whether the shooter or the shooter’s parents or someone from whom he stole them). It may be that they could ‘qualify’ for the weapons as an amateur competition target shooter. (An AR-15 chambered in .223 isn’t a hunting rifle. But it’s good for competitions.)

You are not going to shut down weapon ownership. Given that fact, the limits you can emplace need to be effective — which means dealing with family/friend use of the weapons.