Received: 30 July 2018
Accepted: 14 August 2019
First Online: 20 September 2019
Ethics approval and consent to participate
: The data come from publicly available datasets on mass shootings in the United States: Mass Shootings in America, Mother Jones, and USA Today. All three datasets collect information on mass shootings via media reports, and the USA Today dataset also uses data from the FBI’s supplementary homicide report. As none of these datasets involve human subjects, human subject review is not applicable.
: Not Applicable
: The authors declare that they have no competing interests.