Update: Comprehensive Study of Mass Shootings by Mayors Against Illegal Guns
Feb 22, 2013
Using new data from the FBI, Mayors Against Illegal Guns updated its comprehensive study of mass shootings. The 25 percent increase in incidents — to a total of 56 over the last four years, more than one per month — strengthens its conclusions about where mass shootings occur, what weapons are used, and what other factors are at play:
- Less than 1% of gun murder victims were killed as part of incidents with four or more victims.
- In at least 57 percent of the incidents, the shooter killed a current or former intimate partner or family member.
- Assault weapons or high capacity magazines were used in 23 percent of the incidents, and when they were used, more than twice the number of people were shot and 57 percent more were killed.
- No more than one quarter (23 percent) of the shootings occurred in public spaces that were so-called ‘gun-free zones.’
These findings challenge some of the conventional wisdom about mass shootings, and the report highlights the areas in which further attention and research are needed. Click here to download the full report, and click here to access the full data set.

