You have to address a whole set of complex issues if you want a society where no one is inclined in the first place to drop a concrete block off an overpass on someone else. You have to ensure that people are:

1. economically secure
2. well educated
3. have a strong sense of purpose and idealism
4. have learned a good set of values
5. in short: are happy!

To address those issues in the first place when organizing a society is a far wiser course than seriously neglecting most of those issues and then meeting social violence with greater institutionalized violence in order to supposedly "stop violence".

This is why the Draconian approach to law enforcement has never much impressed me. Like war, it is probably the least intelligent response to an already bad and previously neglected situation. It's a short term fix, not a long term solution to anything.

Now, there are times when a short term fix may be the only way to go...at that moment. But I don't enjoy the way some people gloat over it when they do it. They should have some regret that things were not handled a whole lot better in the long chain of small events that led up to the final problem...and they should learn something from that. You don't build a healthy society on the principle of vengeance.