Team finds universal background checks lower homicide rates

First-ever side-by-side comparison of state gun laws finds states with universal background checks for all gun sales had homicide rates 15 percent lower than states without such laws.

A new study led by Boston University School of Public Health (BUSPH) researchers finds states with universal background check laws had homicide rates 15 percent lower than states without them. Published in the Journal of General Internal Medicine, it is the first study to directly compare state gun laws in one statistical model, finding that limiting what guns are sold may be less effective than limiting who can buy them.

"Research has shown that the greatest risk factor for violence is a history of violent behavior," says lead study author Dr. Michael Siegel, professor of community health sciences at BUSPH. "Public health advocates should prioritize policies designed to keep guns out of the hands of people who are at a high risk of violence based on their criminal history."

Siegel and his colleagues created a unique statistical model to directly compare 10 different firearm laws and their effect on state homicide rates from 1991 to 2016, using the State Firearm Law Database, a public access database created by the BUSPH research team, and Centers for Disease Control and Prevention (CDC) data. The statistical model controlled for a wide range of state-level factors known to be associated with higher rates of homicide and suicide.

They also found laws against selling guns to people convicted of violent misdemeanors, not just violent felonies, had an even more dramatic association than universal background checks: the five states with violent misdemeanor laws had homicide rates 18 percent lower than states that did not. In contrast, "shall issue" laws— which do not allow law enforcement officers any discretion in approving or denying a concealed carry permit— were associated with a 9-percent increase in homicide rates.