Mass Killings Past, Present, and Future

Historical Background

In the 1980s, the Federal Bureau of Investigation (FBI) established a system to classify multiple murder, mass murder, spree murder, and serial murder (Fox & Levin, 2014). The FBI defined “mass murderer” as someone who kills four or more people in a single incident; not including themselves, typically in a single location. However, the government has never defined mass shooting as a separate category, and there is no universally accepted definition. Media outlets, gun control and rights advocates, academic researchers, and law enforcement agencies frequently use different definitions when discussing “mass killing”, “mass murder”, and “mass shootings”, leading to different assessments of how frequently such events occur and whether they are more common now than they were a decade or two ago. For example, on February 12, 2010 Amy Bishop, an assistant professor at the University of Alabama in Huntsville shot 6 people, killing three. On October 21, 2012 Radcliffe Haughton walks into the Azana Salon and Spa, where his estranged wife worked, and shot 7 people, killing three. On April 2, 2014, Ivan Lopez shot 19 people at Fort Hood. Miraculously, he only killed 3. Under the 1980 FBI definition with the four victim thresholds, these events would not be considered mass murders.

For previous empirical work on mass killings, see Rummel (1994, 1995), Krain (1997, 2000), Sully (1997). These articles focus mostly on the impact of poverty, ethnic diversity, and political regimes.

While other have used the term, “mass shootings”, Grant Duwe coined the term in his book, Mass Murder in the United States: A History (2007). Duwe (2007) defined mass pubic shootings as “any incident in which four or more victims are killed publicly in a workplace, school, restaurant, or other public place with guns and within 24 hours” (p. 27).

In the early to mid-2000s, scholarly journals were flooded with articles addressing mass murders. The first major grouping of scholarly journals focused on the impact of identity and mass murderers. For example, Leyton (2001) discussed social class and political economy, Wise (2001) focused on race and ethnicity, Mai and Alpert (2000) address gender and masculinity. Schiele and Stewart (2001) looked at school shootings, race, and gender. Klein (2006) looked at mass murder and homophobia, masculinity and socioeconomic status. Aitken (2001) explored school shooter’s demographic traits and the intersection of racism, sexism, and ageism.

The second major grouping of scholarly journals that focused on mass murderers indicated that suicidal motives played a major role in many offender’s behavior. For example, Mullen’s (2004) analysis of five mass murderers who survived found that all these offenders had significant psychological problems and had planned to kill themselves. Similarly, Newman, Fox, Roth, Mehta, and Harding (2004) found evidence that almost 90% (88.9) of the school shooters they studied from 1974 to 2001 had struggled with suicidality, mental illness, or depression. Finally, in their follow-up study of school shooters from 2002 to 2008, Newman and Fox (2009) found that 100% of the offenders had struggled with suicidality, mental illness, and/or depression. It should be noted that in most mass killings, the offender does, in fact, commit suicide rather than face the incoming police. Even this, however, is not absolute as we’ve seen a relatively increasing number of mass killers (active killers) engaging with the police. Most have lost that engagement.