Mass murder is defined by the FBI as the killing of three or more people in a single event or in the same day (Petersen & Farrington, 2007). Mass murderers are complex and can be examined by the many factors that regularly appear among them, such as violence precipitating events, weapon of choice, and mental illnesses. The motivations and methods for committing mass murder are easily broken down into specific groups, and through the examination of these definitions and specific cases there is much to learn about the mind of a mass murderer.
Throughout history mass murder has not been a problem to the same level and in the same sense as it is today. A related occurrence that is seen in history, which can be studied for its similar preparation and organization, is genocide. Genocide, an international crime, is a large-scale form of mass murder, in which many people are killed in a string of independent events because of prejudices or war (Reisman, 2008). Killing a large group of people takes a high level of organization. The logistics of how to do it, where to do it, where to dispose of the bodies, among other things must be examined before killing begins (Reisman, 2008). The only similarity to the 21st century version of mass murder is the predatory violence involving extensive planning and little to no emotion involved in the killing (Meloy et al., 2004). However aside from that it is difficult to compare the two events because genocide has many killers and can take place over extended periods of time. For example, during the Holocaust Nazi Germany systematically exterminated millions of Jew over a period of three years (Reisman, 2008). This trend is relevant due to the death of more than three people in a single event (Stone, 2007), a single event that occurs repeatedly. Also due to the presence of a single charismatic leader and a single plan genocide can be examined as if the leader is the killer and the followers are the weapons (Reisman, 2008). The event of mass murder as known today, postal workers going postal and school massacres, has been emerging as a more regular occurrence throughout the last century (Lester, Stack, Schmidtke, Schuller & Muller, 2005). Starting with the Vietnam War era, there have been an increasing number of mass murders, which share a causal link to the increased militarization of American Society. The introduction of semiautomatic weapons in mainstream society gives the opportunity for explosive and gratuitously violent events such as have been seen in recent years (Hamamoto, 2002). The increase in graphically violent war movies and first person video games, full of violent images and massive destruction, lend a hand in the building of a society that is hyperaware of war level violence.
The central legal concern associated with mass murder has been gun control. More specifically the aftermath of Columbine can be examined to show the range of gun control...