Yet the fact remains that even if every last mass murderer were mentally ill, they *still* have access to WMDs. There is no reason why hunters, hobbyists, collectors, etc. cannot have their constitutionally-guaranteed right to own firearms, but just not military-style assault weapons.
A gun, even an AR-15, is not a WMD. That kind of exaggeration is why Bush the Lesser, with Democratic support, took us into Iraq.
The guns, again, are not the problem. It's mentally ill people, most of which telegraphed their intentions, who are the problem. Note that most of them committed suicide after committing mass murder. Sometimes by themselves, sometimes with the assistance of the police. That's insane.