the overcontrolled hostility type
chronically aggressive type
the just plain bad and angry
What happens in the mind of a killer?
A killer has to overcome a lot of things to be able to pull the trigger and commit the crimes they do. Pulling the trigger is a hard thing to do. Being the evil one is not easy no matter what you may think. Our human brains are wired for compassion, empathy, and guilt. Not everyone has the same amount of these things but still......we all have them. So what causes someone to get to the point of killing someone? No job, no money, stress, and probably some childhood experiences.
Some people don't have someone to talk to about their problems. They may not even have something to do that they enjoy to help them relieve stress. This results in a strong inner pressure of anger . Sometimes it comes out as an urge to kill. Often the wrong person gets killed not the original target.