Annual Risk of Mass Shooting Fatality in U.S. Estimated at 1 in 9.1 Million

Washington D.C. – The annual probability of an individual being murdered in a mass shooting in the United States from 1966 through 2024 was approximately 1 in 9.1 million, with the chance of being injured standing at about 1 in 6.4 million per year. These statistics were presented by Alex Nowrasteh, Vice President for Economic and Social Policy Studies at the Cato Institute, in a recent briefing paper titled "Risk Analysis of Mass Shootings Committed by Immigrants and Native-Born Americans."

The comprehensive study, spanning 59 years, identifies 298 mass shooters responsible for 1,733 murders and 2,459 injuries during the period. Nowrasteh's analysis defines a mass shooting as an "indiscriminate rampage with a firearm in a public place or place of business that results in at least three victims killed by the attacker." This definition synthesizes various government and private research definitions.

Further breaking down the data, the report indicates that 255 of these mass shooters were native-born Americans, while 43 were foreign-born. The annual chance of being murdered by a native-born mass shooter was approximately 1 in 10.5 million, significantly higher than the 1 in 68.4 million chance associated with foreign-born mass shooters.

Despite the profound impact of these events, the study highlights their relative rarity within the broader context of U.S. homicides. Murders from mass shootings accounted for roughly 0.15 percent of all homicides between 1966 and 2024, though this percentage has seen an increase in recent years. The year 2017 marked the deadliest period for mass shootings, with 14 incidents resulting in 130 deaths and 959 injuries.

Nowrasteh's research emphasizes that while mass shootings are serious crimes that garner significant public and media attention due to their brutal and indiscriminate nature, they remain statistically uncommon. The findings aim to provide a data-driven perspective on the individual risk associated with these events in the United States.