People can learn from the mistakes in Vietnam countries where they enslave elephants. Deprive them of food, beat them, chain them, hurt them, force them to do tricks. People think elephants are mindless stupid animals but they are actually very smart. So it's no wonder the odd time you have an elephant that goes on a killing spree after killing the person who hurt them.
Human's are no different but some bullies decide to make life a living hell for one person. I have no sympathies for bullies not because I was a victim but because I saw it day in and day out. So when you can say "Hi to your school shooter and walk past him in the hall way and tell him where you can find his tormentor". If you treated the shooter person with respect and compassion he will remember this and spare your life. Are these simple things so hard to present?