We are headed the other way with gun control, many states, particularly here in the south have already eliminated the need for permits and now endorse "open carry". A quick Google search shows that we already have the second or third-highest incarceration rate on the planet. I'm not sure we can afford to lock up too many more. I suspect the high crime rates and mass shootings are related to ever decreasing quality of life for most Americans. I suspect that in most cases, people that have a good-paying job, medical benefits, and generally good quality of life don't resort to violence nearly as often as those with nothing left to lose. Think of America in the late 50s and very early 60s.
I also think we are already considered an extremely dangerous country to travel to. The U.S. Educational system is already considered to be defective in comparison to other civilized countries. We're the only country that thinks it's normal to saddle college graduates with a lifetime of debt needed to purchase an education. In most other countries it's free. We are here because profit is king.