violence is a manifestation of an underlying problem (or problems).The cure for violence is common sense criminal controls.
The cure for violence is to find the root cause. We already incarcerate more people per capita than most countries. While I'm all in favor of locking up violent criminals (or public execution), that doesn't help us with the next nutjob in the queue.
The question shouldn't be "how do we keep guns/knives/rental trucks loaded with fertilizer/fuel) out of the hands of the nutjobs, but rather "what in the world would cause someone to murder a bunch of innocent people?"
I realize in a lot of cases (unfortunately, after its too late) a long list of "obvious" hints/signs/activities get 'discovered' and the path was obvious, but still...even if "mass murderer #17" was bullied, fired, and disgruntled how/why do they have no sense of right & wrong, no belief in the value of human life?
Obviously, finding the real problem (or problems) is difficult (and finding a solution even more difficult), but its further complicated by our sound-bite, quick-fix,short attention span society, which just enables politicians to propose solutions that only address the symptoms. Kinda like western medicine :-0
oops, I may have gone off on a tanget.... :-)