"The Process of Violentization"  describes four stages in the development of serial killers.
Stage 1 Brutalization: Within this stage, the subject is forced into doing violent acts by a member of their primary group.
Stage 2 Belligerency: In this stage, the subject reinforces his warlike attitude to the situation by a method of different steps. They take personal responsibility to the fact that they started the brutalization stage to begin with. In turn, they feel like they must lash out in order to forget about what they did to begin with. The subject feels like the only way for them to make right to the situation is to keep acting out. With this repeating behavior they get emotionally attached to what they are doing. Because of this emotional attachment, the subject feels like anytime they are provoked, they can end the feeling by continuing the violent acts.
Stage 3 Violent Performances: The subject continues to act out violently and they feel that they get inner confidence by acting like this and that in turn builds their self esteem. With their actions being executed, they feel like they get a knack for it and they incorporate it into their daily activity. In this stage they feel most comfortable with what they are doing and do not feel like they are doing anything wrong. The subject feels like they have gained celebrity status to what they are doing, and within this stage is the defining moment of whether or not they will continue to do what they are doing.
Stage 4 Virulency: Once the subject has made it to this point, they feel like whether or not their fame is notorious or not, they believe it to be a good thing. This stage is also known as the need to show off. They feel like they can move on to bigger and better things if they wanted to and the subject tries to. They have an overcoming feeling of being invincible and that nothing can stop them, so they continue these violent acts. After this stage has been completed they are now considered to be a criminal and there is no stopping the subject to what they may do next.