Steps to reduce violence.
This goes back to communication, socialization and a really, really poor educational system. At the core, social violence is an income/power/communication issue.
How successful people are generally depends on how well they communicate with others. Poverty level people tend to be predominantly Kinesthetic in their learning and communication styles. Typical "talk and chalk" education doesn't address kinesthetic learners, so, students in poverty level communities tend to feel that being "schooled" is to suffer a humiliating defeat. (Listen to M.C. Hammer's "can't touch this" for an example of the popular use of the word "schooled").
We actually train each other to ridicule and dismiss learners who are predominantly kinesthetic.
Properly educating and socializing people improves their employment possibilities, which helps stabilize society more than almost anything else.
In addition, Pavlovian behavior modification, "punishment/reward", works only when it is rigidly consistent. Typically values change from teacher to teacher, and teacher to parent. Normally students learn to adapt to the current authority figures values. This doesn't work well if the parents and teachers have different value systems. The adaptive authority process often teaches disrespect for parents, typically becoming "critical" around teen age years. Students often learn their parents are not the predominant authority figures in their lives and feel no obligation to listen to them.
To address the problem we need to address kinesthetic learning styles and be more adaptive to individual students learning styles.
Standardized tests are helpful in this regard because they identify students that are not responding to standard educational processes. Rather than use them for identification of non-standard students, teachers and school administrators often use them to humiliate students and then complain about being forced to humiliate students rather than implement expensive alternative or individual education.
Once we address learning styles, we need to stop using "punishment/reward", Pavlovian behavior modification. We need to replace it with positive reinforcement and pretty much eliminate punishment, except for violent situations that result in bodily harm. Pavlovian punishment/reward creates a dependence on authority structure.
Third, we need socialized medicine with comprehensive mental health care so that people with issues can receive help when they need it.
Fourth, as income inequality increases society destabilizes. IRS SOI Tax Stats for 2013 publish the Adjusted Gross Income for 2013 collected from 1040s. The range, 99.7%, is $1M to $0. That makes the middle $500,000.00. 85% of returns report an income of less than $100K. There is no middle class in the United States.
Compensation should be limited to 100 times the compensation of the lowest paid worker, including temps and contractors. Minimum wage should be increased to a living wage. Henry Ford overpaid auto workers and the results of that action are historic and non-intuitive.
Disposable income is critical to social stability and economic growth. Personally, I'd make a flat tax of 50% of all income over the previous years 75% range. In 2013 about 75% of people made less than $75K. I'd tax the upper 25% at 50%. Someone making $100K would pay $12.5K in taxes and someone making $1M would pay $462,500.00 in taxes.
This places the tax burden on those who are less likely to spend all their discretionary income.
These are sweeping changes, and the resistance will be extreme, but, it's pretty much change or die. There might be alternative solutions capable of achieving the same results, but, I have not heard them.
At the core, social violence is an income/power/communication issue.
If we keep doing the same things, we'll get the same results. If we oppress people more, they will rebel more. To battle social violence we need to improve our community socialization institutions, schools, provide free mental health care and reduce income inequality.