US mass shootings, 1982–2023: Data from Mother Jones’ investigation

This database originally covered cases from 1982 to 2012 and has since been updated and expanded numerous times. For analysis and context on this data—including how we built the database, and a change to the baseline for victim fatalities with cases dating from January 2013—see our Guide to Mass Shootings in America, which includes an interactive map documenting all of the cases. [Editor’s note, 4/24/22: Readers may wonder why this database does not include the New York City subway shooting on April 12, the school shooting in Washington, DC, on...