Drugs are illegal
There's plenty of laws regarding the use; purchase and sale of them
Doesn't ever seem to prevent ANYONE from ever finding or buying drugs.
Ban a gun that's been in existence?....sounds great, but they will find there way into the hands of people like this nut job today.
As for what else could he use to inflict this much damage? Have you watched the news in the past 5-10 years? Trucks, pipe bombs, knives, etc..all used by other nut jobs called terrorists.
We can start confiscating guns of anyone convicted of any crime, even traffic violations. If you commit a crime while in possession of a gun, you go away forever. Convicted of injuring or killing another human with a gun, death penalty. If you start treating it like an economics issue, behaviors WILL change. Everyone has a price and people can be scared into action.