Mass Murder

The influence of demographic, situational, psychological, and motivational factors in mass murder attacks

“…Mass murder is the killing of multiple unknowing victims (not including the perpetrator) at an unspecified, unforeseen moment, usually committed by a sole perpetrator (Fox & Levin, 2003;Holmes & Holmes, 2001;Palermo, 2003). Other criteria have also been used to supplement the definition, such as minimum number of victims (Bondü & Scheithauer, 2015;Bowers et al, 2010;Fox & Levin, 2003;Knoll, 2012;Levin & Madfis, 2009), location of the attack (Aitken et al, 2008;Dietz, 1986), motivation behind the murder (Duwe, 2007;Hempel et al, 1999), the type of weapons used in the event (Duwe et al, 2021;Gill et al, 2017), and the number of perpetrators involved (Fox & Levin, 2003;Holmes & Holmes, 2001;Palermo, 2003). One of the original operationalizations of mass murder by the FBI was based on the number of victims killed: two or more for spree killings, three or more for serial killings, and four or more for mass killings (Douglas et al, 2013;Ressler & Burgess, 1985).…”

“…The minimum number of victims ranges between two (Levin & Madfis, 2009;Palermo, 1997), three (Aitken et al, 2008;Hempel et al, 1999), and four (Duwe, 2016;Fox & Levin, 1998;Knoll, 2012) with some scholars arguing a larger number better satisfies the requirement for the definition (Bondü & Scheithauer, 2015;Fox & Levin, 2003). Most researchers can agree that if the perpetrator dies during the public mass shooting, they are not included in the victim count (Fox & Levin, 2021;Fridel, 2021;Huff-Corzine et al, 2014;Huff-Corzine & Corzine, 2020;Krouse & Richardson, 2015).…”

“…The perpetrators often have no plan to escape their attacks, and may either kill themselves or force police to kill them, also known as suicide by cop (Knoll, 2012;Meloy et al, 2001).…”

“…Spree murders are categorized as the killing of several victims over the span of a few hours or days over various locations (Gresswell & Hollin, 1994;Knoll, 2012). These killers often put little effort in disguising themselves from detection which could explain why these killings are stopped by either the perpetrator taking his own life or being apprehended by law enforcement (Duwe, 2007;Fox et al, 2018).…”

“…As presented above, there is overlap in the domestic terrorism and mass shooting typologies are typically created to distinguish two varieties of offenders. These were historically categorized this way because of law enforcement or legal statutes, but several mass shootings irrespective of their political motivation have intended to cause fear and panic to the American public, which is inherently terroristic in nature (Borum, 2013;Bowers et al, 2010;Knoll, 2012). Without such comparative analyses on domestic terrorists and mass shooters, it is unknown whether the factors that contribute to the lethality of domestic terrorism attack differ from those of mass shooters.…”