Variation in Rates of Fatal Police Shootings across US States: the Role of Firearm Availability.

The USA has very high rates of homicide by police compared to other high-income countries, with approximately 1000 civilians killed annually. The overwhelming majority of these police homicides are fatal shootings. Over the past 5 years, several comprehensive, real-time, data repositories, drawn largely from news reporting, have kept track of incidents in which civilians die during an encounter with the police and have become widely available. Data from these repositories, which are more complete than data available from federal data systems, have been used to explore fatal police shootings of civilians, often with a focus on racial disparities in police shootings of unarmed civilians, and have consistently found that police are more likely to shoot unarmed African American men than unarmed White men. Although numerous studies have examined how rates of police killings of civilians are related to several ecologic determinants of these events, no peer-reviewed study to date has examined the extent to which variation in police involved firearm homicides is explained by firearm prevalence while adjusting for violent crime rates (the most well-established ecologic factor associated with fatal police shootings). The current cross-sectional state-level analysis uses data on the number of civilians shot and killed by police in the line of duty, aggregated over 2015-2017. Data come from the Washington Post's "Fatal Force Database", which assembles the information from news reports and other sources. Data provided include information on whether the victim was armed, and, if so, with what weapon. Explanatory ecologic variables in our models include the violent crime rate, the percentage of the state population that is non-White, poverty rate, and urbanization, along with a validated proxy for firearm prevalence. We find that rates of police shooting deaths are significantly and positively correlated with levels of household gun ownership, even after accounting for the other explanatory variables. The association is stronger for the shooting of armed (with a gun) rather than unarmed victims.