ABSTRACT
This study uses a crime script analysis to examine far-right, far-left, and jihadist-inspired ideologically motivated mass shooters (IMMS) in the US (1970-2019). This work provides a comparison of incident rates and shooter backgrounds, as well as the preparation, execution, and conclusion of attacks. When comparing the three IMMS types, findings indicate far-right incidents were most common, far-left shooters were largely Black Nationalists, and jihadist-inspired shooters had more success in life (college graduates, employed, married, parents). During initial preparation, IMMS often leaked violent intentions and had facilitating conditions including criminal, domestic violence, and military histories. Jihadist-inspired shooters had more planning, and far-left shooters often accessed guns illegally. During attack execution, IMMS incidents often occurred in the South and involved open-space and/or unrestricted access locations. Jihadist-inspired shooters targeted government locations more often, while far-left incidents often occurred outside with law enforcement on the scene. During attack conclusion, IMMS incidents often ended quickly and involved gunfire with police. Jihadist-inspired shooters had a higher rate of victim casualties, and far-left shooters had a higher rate of police casualties. Far-right shooters had a higher number of victim and police casualties overall. A discussion of findings contextualises IMMS threats and explores strategies for countering the phenomenon.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Notes
1 The 1970 start date is used because it aligns with previous terrorism (LaFree & Dugan, Citation2007) and mass shooting (Capellan, Citation2015) research.
2 This study excludes failed incidents and foiled plots that did not incur any victims.
3 Sometimes referred to as ‘public' mass shootings (Capellan et al., Citation2019).
4 The inclusion of co-offenders was sparked by the 1999 Columbine shooting, arguably the most high-profile mass shooting to occur in the US (Silva & Capellan, Citation2019). Its continued inclusion, particularly regarding ideological incidents, is rooted in the recent high-profile 2015 San Bernardino shooting.
5 The GTD included four incidents from the initial list of 517 mass shootings that were not coded as ideologically motivated during Step 2: 1999 Columbine High School, 2017 Route 91 Harvest Music Festival, 2014 Isla Vista, and 2018 Hot Yoga Studio. These incidents were excluded for two reasons. First, there is debate in terrorism scholarship over the inclusion of the Columbine and Route 91 shootings, and as such, this study took a conservative approach by excluding them. Second, the Isla Vista and Hot Yoga Studio shootings were motivated by Incel ideology, which was excluded from the current study’s ideological definition.
6 The four unconfirmed cases included two far-left cases and two far-right cases.