There are so many layers to the issue at hand. IMO, primarily it is the lack of empathy for your fellow human, degradation of the family unit and many times, parents too busy to actually parent and invest in their child's life. Rampant divorce, narcissism and it's effect on parenting, living above means so the kids are left alone with 24/7 bombardment of social media and such all play a huge role.
Like I said, there's many, many layers here.
Banning guns, stricter gun laws, magazine limitations, ammo tax, etc won't do shit. It'll have to begin at the family and society level.