Investigating 55 years of mass shooter statements in the United States: A study of perpetrators’ stated motivations and their association with attack severity

ABSTRACT

Mass shootings are a prevalent and terrible problem in the U.S. As a foundation for communication-focused research into the media-related causes and effects of mass shooters’ stated grievances, and guided by the model of intuitive-morality and exemplars (MIME), we content-analyzed N = 178 statements from 119 U.S. perpetrators who committed mass shootings between 1966 and 2021 to identify the motivations they communicated for their attacks. Findings revealed that mass shooters who communicated any motivation – possibly indicative of their rationalizations – killed and injured more people than those who did not communicate their motivation(s). Overall, shooters most often described their motivations as driven by power and relatedness concerns. Those who expressed ingroup-loyalty and relatedness motivations injured the most people, while power-motivated shooters injured the fewest.

KEYWORDS:

• Mass shooters
• manifestos
• altruistic motivations
• egoistic motivations

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Upon request to the corresponding author, the current study’s data and entire database of statements are available to researchers interested in advancing knowledge in this area. In accordance with the suggestions of the “No Notoriety” campaign and Lankford and Madfis’s (2018) proposal to deny offenders the attention they often seek, we refrain from using the names of any mass shooters in this paper or posting our database in a public repository.

Notes

1 We provide more details on this definition in our method section.

2 Such advancements would also help to more clearly parse out the theoretical utility of the MIME’s processes and could help address legitimate concerns that the inclusion of such a wide array of altruistic and egoistic motivations from moral foundations theory, self-determination theory, and universal human values may make it unfalsifiable.