How Do You Indoctrinate Someone to Be Like a School Shooter?

i think hatred most commonly stems from one of two places. Either the stems from conditioning, where you're taught from a young age to hate someone else. The second place is that often times hatred comes from hurt. What actually terrifies me some about some of this like emerging, i think deranged behavior is may may be a better way to put it,. I'm not so sure that this is a malfunction of the mind or the brain.