A Descriptive Analysis of Mass Shootings in the United States From 2010 to 2020: The Relationship Between Firearm Dealership Density and Proximity to Mass Shooting Sites and a Comparison With McDonald's and Starbucks Retailers

The public health community needs to better understand the complex factors that contribute to mass shootings in the United States (US). We explored how firearm dealership density related to geographic distance from mass shooting sites in the US in 2010-2020, and compared it with the corresponding density of Starbucks (Starbucks Corporation, Seattle, Washington, United States) and McDonald’s (McDonald's Corporation, Chicago, Illinois, United States) outlets. We obtained locations of firearm dealerships, Starbucks, and McDonald's retailers, as well as mass shootings across the contiguous US from 2010 to 2020. We mapped buffer rings, at 1, 5, 10, 30, and 50 miles around the locations of each mass shooting. We compared the per area and per population density of the dealerships and the two types of retailers around mass shooting sites within each buffer ring. We identified 67 mass shootings from 2010-2020. We mapped 54,722 firearm dealerships, with 28.1% located within 50 miles of mass shootings. Within a 50-mile radius of shooting events, there were an average of 0.30 dealerships, while there were only 0.14 Starbucks and 0.12 McDonald’s outlets per 10 square miles. There was an incremental reduction in the density of firearm dealerships, Starbucks, and McDonald’s as the distance from the mass shooting site increased. Density per population did not show a similar relationship. Our findings suggest that the availability of firearms deserves more study as a contributing factor to mass shootings in the US. The high number, area, and population density of firearm dealerships compared to the other two retailers illuminate how numerous firearm dealerships are compared to common retailers in the US.