According to data compiled by Grant Duwe, author of "Mass Murder in the United States: A History", Mother Jones, and Washington Post Link to data provided by the Washington Post: https://washingtonpost.com/wp-apps/imrs.php?src=https://arc-anglerfish-washpost-prod-washpost.s3.amazonaws.com/public/CFPAP5NQF5CVRJSU7QO5YN435I.jpg