Columbine. Sandy Hook. Uvalde. Parkland. Las Vegas.
When most people picture a mass shooting, they think of high-casualty attacks that dominate national news, often at schools. In January 2025, we surveyed 10,000 U.S. adults and asked them to name the first mass shooting that came to mind. Those five were the most common answers, events seared into public memory.
But that picture is incomplete. Many mass shootings never trend on social media or make the evening news. This summer, for example, both Denver and Minneapolis, where we undertake much of our research, experienced mass shootings in busy public spaces that drew limited attention outside their states. They were still “mass shootings” as the Gun Violence Archive defines them: incidents in which four or more people are shot, excluding the shooter, regardless of whether anyone dies. They documented that 3,109 of these incidents occurred between 2020 and 2024…