A new study published in the American Journal of Public Health concludes that high rates of gun ownership triple the likelihood that law enforcement officers in the US will be killed on the job. These findings run counter to other ideas regarding high police fatality rates, including the expectation that police are more likely to be murdered simply because they are more likely to encounter violent criminals.

Law enforcement officers have three times the national average risk of being murdered on the job. This high occupational homicide risk exists despite officers’ training in dealing with violent criminals and protective equipment, as well as the fact that they carry their own firearms. Nearly all of these homicides are committed with firearms, and a previous study showed that only 10 percent of these deaths were caused by officers’ own guns.

These researchers probed the relationship between the prevalence of gun ownership and police deaths on the job. Using data from an FBI database of law enforcement officials’ deaths, they calculated police homicide rates by state. For gun ownership data, the researchers obtained the mean household firearm ownership per state using an annual nationwide survey known as the Behavioral Risk Factor Surveillance System.

Using a regression statistical analysis, the authors found that occupational homicide for law enforcement was correlated with higher rates of firearm ownership. The analysis controlled for the violent crime rate, which indicated that these higher rates of homicide couldn’t simply be attributed to more frequent violent crimes occurring in states with higher rates of gun ownership. Instead, higher rates of law enforcement homicides were associated with more frequent encounters with violent criminals and with more frequent exposure to situations where privately owned firearms were present.

However, there were limitations to this study related to the gun ownership rates. There is no standard measure of annual firearm ownership rates—while the Behavioral Risk Factor Surveillance System is widely considered to be the best measure available, questions about gun ownership were only included in the survey for three years: 2001, 2002, and 2004.

The authors conclude that higher levels of private firearm ownership increase the likelihood that law enforcement officers will face life-threatening situations on the job. The authors state that a 10 percent increase in firearm ownership at the state level correlated to 10 additional law enforcement homicides over the 15-year period that was examined in this study.

Officers in states with higher rates of gun ownership had three times the likelihood of being killed by a firearm when compared to officers in states with low gun ownership rates. The authors conclude that states should consider mechanisms for reducing the rate of firearm ownership as a way to reduce on-the-job homicides of law enforcement.

AJPH, 2015. DOI: 10.2105/AJPH.2015.302749 (About DOIs).