Public mass shootings in developed countries: uncovering stability and change at the turn of the century

This study examines the stability and change in public mass shootings in developed countries outside of the United States (2000–2021). Public mass shootings refer to incidents involving public/populated locations, random/symbolic victims, and at least four fatalities. Results identified an increase in the frequency of attacks in developed countries, although particularly deadly incidents remained relatively consistent. Offenders were commonly and consistently male, middle-aged, single, and diagnosed with a mental illness. Incidents often involved handguns, more than one firearm, and open-area locations. Offenders were often motivated by a desire for fame; although, early fame-seekers were younger, school shooters, while recent offenders had far-right ideological beliefs. Other changes included an increase in offenders obtaining their firearms illegally, using assault rifles, diversifying their target locations, and being shot and killed. This provides the first step for understanding mass shooting trends in the often-overlooked developed countries outside of the United States.