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.
[Editor’s note, 8/27/25: Readers may wonder why this database does not include the August 2025 school shooting at the Annunciation church in Minneapolis, or previous gun rampages in April 2022 in the New York City subway and at a school in Washington, DC, or the many other such attacks in which fewer than three victims died. For additional context on the challenges of defining and tracking mass shootings, and on our approach, see this piece and this piece.]
You can scan the underlying spreadsheet by clicking here and download the database in its entirety (in CSV format) by clicking here.