This isn't about the tragedies that have erupted, as they are wont to do over the decades. Obviously, it's all horrible and my prayers, seriously, have gone out to those afflicted.
What I would like to know is, barring we ban guns, gasoline, lighters, twine, fertilizer, trucks, bleach, whatall, what would one have done to STOP the Sandy Hook guy beforehand, or the Colorado guy, or whatever other guy who is nuts who wants people dead BEFORE that person did what he did? Because those people WILL succeed at what they do regardless.
Would you have increased healthcare options and medications, of which many people don't avail themselves, in which case you'll need you some healthcare/med police? Would you implant a chip in your potential nutball candidate that knows, sufficiently before mayhem occurs, when such mayhem is planned and therefore incapacitates that nutball? Do you have some secret source of research that you're hiding from us?
Would you require constant custodial care of those you deem potential nutballs? Not actual, certified nutballs, just potential nutballs, which includes a large percentage of the human race.
What would you DO or have done to stop whichever of these peeps beforehand?
Nothing. Because they hadn't done anything beforehand. So, what makes you think you can control this with restrictions on the rest of semi-normal society?
It's quite amazing. We're doomed to dissolve in stupidity-until the media forgets about it in a week, which is soon.