There are many different definitions to serial murder. Several authors have similar definitions with minor differences. One of the differences is that there is a time between killings called the cooling-off period. This time differs between definitions. The definition used here states that the cooling-off period is noticeable and that at least three people must be killed for it to be named serial. Serial murder is also put into categories depending on if the victims are murdered at the same time (Myers, 2004). Three categories of serial murder as defined by Knight (2006) include mass murder, spree murder, and serial killing. Mass murder is explained as killing three or more people at one time and one place without a cooling-off period. Spree murder is killing more than three people in thirty days. This type of murder usually happens with petty crimes committed during the spree. Lastly, serial killing is described as killing three or more people in more than thirty days with a noticeable cooling-off time in-between. Another deciding factor is if the murderer is successful, meaning that they were never apprehended. Or the serial killer can be put into the category of unsuccessful, meaning that they were tried and found guilty in a court of law. These unsuccessful serial killers are able to be studied to learn the reasons for psychopathy. The research from unsuccessful serial killers leads to figuring out and capture of the more elusive killers. The successful murderers are the ones that need to be studied so that society can learn how to prevent them (Yu & Raine, 2010).
Focusing on Knight’s (2006) definition, serial killers can be classified as either organized or disorganized. Both of these types are thought to have some of the same basic identifiable characteristics. The serial murderer might have had a history with animal cruelty, taken trophies, had trouble with the law, became versed in manipulation, or planned the kill beforehand (Knight, 2006). Organized serial killers can also be classified as lust or thrill serial killers. These types of murderers won’t stop until caught. The killers classified as lust usually stalk their victims and plan their kills. Mutilation of the body is usually common in these types of killings. Lust killers get more violent with each crime committed. On the other hand, thrill serial killers are separate in that they derive their pleasure from the process of killing. They don’t usually dismember the body because there is no thrill once the victim is dead (Knight, 2006). These definitions of organized murderers are thought of when thinking of popular television shows such as Criminal Minds or CSI. However, thrill and lust killers are not the only categories displayed on criminal justice shows.
Psychopathy is another word that is often used to describe serial killing. It is a word to describe the actual disease that serial killers have. Instead of being a more pathological disease, psychopathy is more of a mind disorder. Psychopathy also has many different definitions, but there are specifically three personality types that lead to serial killing. The first, Farrington (2005) insists, is an arrogant, deceitful interpersonal personality (ADI). This includes manipulating others, superficial charm, and an overactive sense of self-centeredness. The next personality type is deficient affective experience (DAE). The traits of which are low empathy and a failure to take responsibility for one’s actions. The third personality is impulsive/irresponsible behavioral style (IIB). This is shown by seeking excitement, failing to think before acting, and having to live off of others (Farrington, 2005). These three personality traits of psychopathy include behaviors found in most serial killers. The classifications of these characteristics and of serial murder will be used throughout the essay.