Capturing a kook before they kill is quite easy. You see, they always give off these loud warnings before they go off. Therefore locating a potential mass shooter who is stockpiling weapons and making threats or posting ominous nonsense on the internet is far from impossible. Society has actually missed opportunity after opportunity to capture and study these creatures.

Now here is where the counter intuitive solution arises...

The legislation needed is not primarily gun legislation...it is mental health legislation that permits authorities to place someone under arrest and observation in a hospital setting to diagnose them.