Well, this speaks to larger societal problems, doesn't it? As the saying goes, "guns don't kill people, people kill people". But, if the "wrong" people don't have access to a firearm, they can't kill anybody with one. Of course, with determination and planning, someone can make a bomb, drive through crowd, hijack an aircraft, etc. However, if there were no guns available, how many people will expend the time, effort and planning to commit their crimes with other methods? There are always knives, but they require someone to get "close and personal". A lot fewer people would be willing and/or able to commit their attacks in such a manner.
With such a quantity of weaponry in circulation, any new regulations - or more strict enforcement of current ones - would take generations to have a noticeable effect.
Maybe it's time to address the lack of social mobility.
Poverty, lack of social mobility, government distrust contribute to U.S. gun violence - UPI.com