The purpose of this paper is to examine the crime of murder and the theoretical causes of this behavior. There are nine general theories that will be focused upon, along with a critique of each and as a whole. Murder (Homicide) is defined as the killing of one human being by another human being (a person that is born and living). There are four forms of homicide. First degree murder, felony murder, second degree murder, and manslaughter. For all practical purposes, this paper will focus on first degree murder and it's causes. This form of homicide must include the intent to kill trough one of the following: premeditation, atrocious murder, deliberation, lying in wait, bombing or poisoning, or torture.