Here's another thing that is desperately needed in the USA:

A national health care plan that provides equal and free medical care for every USA citizen so that ordinary people's lives are not constantly threatened by ridiculously high medical expenses that they cannot possibly afford.

We have that in Canada. Can you imagine the amount of stress that is taken off people when they know that they have such coverage? We pay for it through our taxes, naturally, and that's fine with me (although I have personally barely cost the Medicare program anything over the years). I don't mind paying taxes for that, because it's there if I need it, and that's good to know.

Every other western democracy has a publicly financed national health plan in place. Only the USA lacks one at this point...yet the USA spends far more per capita on health from the GDP than Canada does! About 10% of the Canadian annual budget goes to health expenses, while 17% of the USA annual budget goes to the same!

*****

What I am suggesting, in a nutshell, is this: Find out what is causing maximum stress to many people in your society, and deal with it effectively and creatively, and reduce those stresses on your citizenry, stresses which are usually financial, situational, familial, and psychological.

If you reduce the most common types of stress on your citizens through various forms of responsible and progressive social policy, you WILL see a commensurate drop in the frequency of violent crimes. I guarantee it. A society is only as mentally healthy as the average mental health of its government and citizenry, after all.