Brad Bellick
He became a prison officer at the age of 18 and rose through the ranks. We know that he had some problem with substance abuse because of meeting Sara in the support meeting but we haven�t been given more information on this. In the prison he was corrupt, accepting bribes to decide who would run PI.
He took an instant dislike to Michael and tried to sabotage him repeatedly. When Tweener told him about the escape he tore up the guard�s room but was attacked by Westmoreland and tied up. Eventually he was freed and went after the escapees.
When a disciplinary committee found out about how he was corrupt he was fired. He went back to the home he shared with his mother and was about to commit suicide when he heard that there was large rewards for each of the escapees.