I'm sorry but despite some unfortunate isolated events we can't keep up with the massive amount of gun related violence and mass shootings in the US. It's a big part of your culture and any attempts at gun control have failed.
You do recognize the safest cities and town in the U.S. are those who have high legal ownership of firearms. The gun related violence is very high in cities like Chicago that effectively ban the legal ownership of firearms for most citizens. This leaves the criminals armed and the law-abiding citizens unable to protect themselves.
While I agree that there are steps that can be taken to control the gun violence in the U.S. and I have outlined my thoughts previously in these forums..... taking guns away from law-abiding citizens with no criminal/mental crisis problems is not one of the solutions.