I have been a person that has experienced both sides of the good/evil. Because of that, I have a perspective, on how we can finally cure it, or treat it. More so than, just putting them in jail.
The key is to understanding, why people become evil.
Most of them, do not understand how to get happyness in the normal way. Have low self-esteem, and just can't seem to find a way to get happy.
It sounds like an over-simplification, but it's true.
Most people want to find the simplest of happyness, family, love, kids and some measure of respect and recognition.
But a lot of us do not know how to get there, or to pay our dues, so that we can earn what we want out of life..
But evil is not merely evil, it is also our teacher. By the existence of evil, we appreciate good times and happyness all the more.
Think about this...