France and england have an epidemic of violent crime.
I would believe that if you factor out gang violence you would see that our country is pretty peaceful. (No backup data)
Citizens and senators were supporting it because they had to do something, so they tapped in the dark.
Mass shootings and domestic disputes can be helped if with armed guards at public places and training of people on correct use of firearms to use in self defense.
Incidentally, the us has less suicide rates than a lot of countries with strict gun control. So no relationship there either.
What is clear, is that religious countries, ie. Cleaner cultures, have the lowest suicide rates.