In the U.S., the mentally ill are not forced to seek treatment and it is deemed unacceptable to force them to. We also let many people out of prison, due to overcrowding, who should remain locked up. Those two facts alone have been catalysts to the increasing American violence.
Plus you have a couple decades of video game violence, ever increasing movie violence and glorified thug society. My personal thought is that a "violence tariff" be charged for every instance in any of the aforementioned media...and those funds be used to safeguard the public from "gun violence." Perhaps an armed guard or simply training some of the staff to have armed carry permits, in teh case of schools.
I'm not a gun nut but more people die from motor vehicles in the U.S. and I don't see anyone calling to outlaw cars. Blaming inanimate objects for things living beings do seems an odd "solution."
Guns are illegal in Mexico...the police and drug cartels are killing incredible numbers of people, now defenseless.
Most of the U.S. gun violence, something like 97 percent of it, is inner city drug/gang violence, not legal gun owners. It's mainly media and politicians stoking the fires trying to push their anti-gun agenda while they can play off a disaster. There are already many such laws in place but not properly enforced.
It's more a case of policing the mentally ill and existing criminal element to protect the general pubic...without the ACLU and attorneys crying foul. But you can never protect everyone from all the crazies out there. If someone wants to kill people and cannot get a gun, they will use any other method to do the same thing.
Also....you might notice that, as the U.S. moves more toward a secular society and away from church/religion, violence has increased. I would assume that, as more people do not believe in a "God" that they also have no fear of a "Hell"...so they have less fear of killing people and being punished. Same for the U.S. Government being at an all-time high level of providing free entitlements for citizens...a role that largely fell on churches for hundreds of years; providing for the needy and couseling them. Again, a trend that leads to less "morality" and increased violence.
It's a mess and I don't see it getting any better unless we lose most of the politicians and lawyers and start over.