In this article, the author examines key elements defining mass shootings and the evolution of definitions over time. The article also scrutinises the characteristics of active shooters and the dynamics of these incidents. Finally, it looks at the impact of gun control regulation on the occurrence of mass shootings through the years and by comparison to other developed countries.
On Sunday October 1st 2017 an active shooter named Stephen Paddock, 64 years old, perpetrated the deadliest mass shooting in modern American history killing 58 persons and injuring more than 500 in Las Vegas. The criminal investigation showed that the shooter meticulously prepared the massacre by stockpiling multiple modified assault rifles and explosives, choosing the “perfect” shooting vantage point and planning an escape route.1 However, this tragic incident is not isolated and other active shooters have shown similar level of preparation in the past (for instance James Holmes, Aurora 2012; Eric Harris and Dylan Klebold, Columbine 1999). Once again, the Las Vegas mass shooting reignited the debate on gun control but what do we know about mass shootings? Are they getting worse? Can they be prevented? To answer these questions, this article will shed light on the phenomenon of mass shootings by examining existing academic researches and available government data. This article places an emphasis on the definition of mass shootings, their characteristics and dynamics as well as the ability of our society to prevent them.
What is Mass Shooting?
Mass shooting is an act of extreme violence in which an individual armed with one or several firearms engage in a shooting rampage killing and injuring random people.2 Randomness is an important aspect of a mass shooting because it differentiates these incidents from multiple casualties violence like familicides, hate crimes or gang violence, which target very specific groups of people and have different root causes. Mass shooting and act of terror are not the same either. Terrorism, also known as political violence, is motivated by a political or social cause. For instance, the terrorist attacks that happened in Orlando and San Bernardino used mass shooting as modus operandi as part of a broader strategy of jihadist terrorism. In these cases, mass shootings are a mean (violence) to end (political cause). The vast majority of mass shootings do not fall into this category because they are perpetrated by individuals that have more personal motives such as vengeance and frustration.
It has been established that in 59% of the cases, the perpetrators were carrying two or more firearms and that assault rifles were used in 26% of the cases. In 76% of the cases, the firearms were acquired legally through stores or private sales.
The formal definition and classification of mass shooting has evolved over the years. In 2008, According to the Department of Homeland Security (DHS), an active shooter is defined as “an individual actively engaged in killing or attempting to kill people in a confined and populated area”. In its definition, DHS notes that “in most cases, active shooters use firearms(s) and there is no pattern or method to their selection of victims”.3 Before 2013, the Federal Bureau of Investigation (FBI) provided a more operational categorisation where mass shootings happen when four or more people are killed by one or more murderer(s) in a particular location with no cooling-off period between the murders. More recently, federal institutions and agencies such as the White House, Department of Justice, Department of Education, Department of Homeland Security agree on the following definition: “an individual actively engaged in killing or attempting to kill people in a confined or populated area”.4 This definition implicitly assumes that firearms are used for the perpetration of the crime. These changes in definition impacted directly the number of cases included in studies and affected the comparability of studies conducted over time.
Frederic Lemieux is Professor of the Practice and Faculty Director of the Master’s degree in Applied Intelligence at Georgetown University. He received his doctoral degree from the School of Criminology at the University of Montreal, Canada. During his academic career, Dr. Lemieux has studied violent crimes including terrorism and mass shooting. His research findings have been published in peer-reviewed journal and books.
2. Bjelopera, J. P., Bagalman, E. S., Caldwell, W., Finklea, K. M., & McCallion, G. (2013). Public Mass Shootings in the United States: Selected Implications for Federal Public Health and Safety Policy. Washington DC: Congressional Research Service.
3. “Active Shooter – How to Respond.” Department of Homeland Security. October 2008. http://www.dhs.gov/xlibrary/assets/active_shooter_booklet.pdf
4. Federal Bureau of Investigation (2014). A Study of Active Shooter Incidents in the United States between 2000 and 2013. Washington D.C., Department of Justice.
5. Lemieux, F. (2014). Effect of Gun Culture and Firearm Laws on Gun Violence and Mass Shootings in the United States. International Journal of Criminal Justice Sciences, 9 (1): 74-93.
6. Federal Bureau of Investigation (2014). A Study of Active Shooter Incidents in the United States between 2000 and 2013. Washington D.C., Department of Justice.
8. Lemieux, F. (2014). Effect of Gun Culture and Firearm Laws on Gun Violence and Mass Shootings in the United States. International Journal of Criminal Justice Sciences, 9 (1): 74-93.
9. Duwe, G. (2016). Pattern and Prevalence of Public Mass shootings in the United States 1915-2013. In Wilson, L. (2016) The Wiley Handbook of the Psychology of Mass Shootings. Wiley & Sons, Chichester U.K.: 20-35.
10. Lemieux, F., S. Bricknell, T. Prenzler, (2015) Mass shootings in Australia and the United States, 1981-2013. Journal of Criminological Research, Policy and Practice, 1 (3): 131-142.