If violence is to be controlled, people have to be helped to see it is not the solution to a problem or issue. Controlling guns is not the answer. Guns that would be lethal can be made, stolen, illegally purchased, etc. Bombs can be used and even rocks can be used to kill.
Potentially violent people need to be helped before they do something destructive. They need to be found and helped!
Guns should be the right of any USA citizen should they want to have one. Although assault weapons are questionable for citizens, the USA is not beyond invasion or takeover by outside or even inside groups. Every citizen has the right to protect themselves and their family when needed.
Controlling guns only keep guns from normal people, those who seek violence with a gun will get one somehow anyway.
The USA needs more law following, moral teachings [and beliefs], family values, good examples from those in power at the top of the US government and even family and friends. Those who are abused themselves, angry, frustrated, at a breaking point, or in need of help should receive help in dealing with whatever issue they have BEFORE they break and become violent and act upon it.