Bringing Science to Bear, at Last, on the Gun Control Debate

February’s mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, which resulted in 17 killed and 17 more wounded, horrified people across the country, spurring student walkouts and marches in support of stricter gun control laws, including universal, comprehensive background checks and a ban on assault weapons. But gun debates in the United States have proven to be contentious and intractable. Indeed, even as thousands rally for new legislation, opponents contend that such measures won’t prevent determined criminals from obtaining a firearm and that responsible gun ownership makes communities safer.

In charting a course forward, it is necessary to move beyond “people’s anecdotal opinions,” says David Hemenway, director of the Harvard Injury Control Research Center. He and other researchers are analyzing data and conducting studies with the ultimate goal of informing public policy. It’s a tough task, in part because of a by now well-known piece of legislation called the Dickey Amendment, passed by Congress in 1996 with support of the National Rifle Association. This amendment prevented the Centers for Disease Control and Prevention from using funds “to advocate or promote gun control.” It didn’t ban federally-funded gun research, but the legislation had a chilling effect: from 1996 to 2013, CDC funding in this area dropped by 96 percent.

Against this backdrop, it can be easy to overlook an important fact: Research into gun violence has actually increased in recent years, rising from fewer than 90 annual publications in 2010 to 150 in 2014. Universities, think tanks, private philanthropy — even the state of California — have been offering support. And last Wednesday, governors from six northeastern states and Puerto Rico announced plans to launch a research consortium to study the issue. A December 2017 policy article published in the journal Science describes a “surge” of recent scientific publications. “The scope and quality of gun-related research is growing,” write the authors, a pair of researchers from Duke and Stanford, “with clear implications for the policy debate.” This research has generated significant findings about suicide, intimate partner violence, community health, and the effect of various state-level gun laws.

More than 36,000 people are killed by gunshot in the U.S. every year, making it a leading cause of death in the country, comparable to that of motor vehicles incidents. Among those deaths, nearly two-thirds are suicides. “A gun in the home increases the risk of someone in that home dying from suicide maybe threefold, and the evidence is overwhelming,” Hemenway says.

A conventional view holds that if people really want to kill themselves, they will find a way to do it — with or without a gun. Yet the data suggest that households with guns do not differ from those without guns when it comes to mental health risk for suicide. Instead, the difference seems to stem from the fact that suicide attempts with a gun are usually fatal, unlike attempts with pills, for example. Putting time and distance between a suicidal person and a gun can save that person’s life.

This line of thinking is supported by a recent study published in the Journal of Surgical Research, which found that states with weaker gun laws have more gun-related suicide attempts, which tend to be associated with higher mortality. Rodrigo Alban, a surgeon at Cedars-Sinai Medical Center in Los Angeles, and his colleagues analyzed data on about 35,000 subjects spanning 14 years. Almost two-thirds of the firearm suicide attempts occurred in states with the lowest rating by the nonprofit Brady Campaign to Prevent Gun Violence — mostly states in the South and West. These states had little to no gun legislation, such as background checks, concealed weapons laws, and safe storage laws.

Of course, correlation doesn’t imply causation, and Alban and his co-authors identify a need for research that pinpoints which particular laws have the greatest effect on reducing suicide attempts. But in the meantime, in light of these findings, they conclude that, “Efforts aimed at nationwide standardization of firearm state laws are warranted.”

Another route to reducing gun violence, academics suggest, is to identify risk factors that increase a person’s chances of harming themselves or others. Such individuals could then be considered for gun violence restraining orders. This was the logic behind the 1968 Gun Control Act, which specified narrow categories of people disqualified from buying or owning guns, including convicted felons and people committed to mental institutions. The 1994 Violence Against Women Act and the subsequent Lautenberg Amendment followed to bolster protections for victims of domestic violence, but because they only apply to people who are currently or formerly married, live or have previously lived together, or have shared children, Susan Sorenson, a professor of social policy and public health at the University of Pennsylvania, says they fail to protect a growing portion of the population who are not in marital relationships, who can be just as violent.

A separate study by Carolina Díez of Boston University assessing state laws confirms Sorenson’s conclusions. Domestic violence homicide rates drop by 10 percent in states prohibiting intimate partners with restraining orders from owning guns and requiring them to relinquish them.

Some states have gone a step further and passed so-called “risk-warrant” laws. In 1999, Connecticut became the first to pass such legislation allowing police to obtain a warrant to temporarily remove guns from someone who poses an imminent hazard to themselves or others. Garen Wintemute, an emergency room physician at the University of California, Davis Medical Center and director of the Violence Prevention Research Program, advocates for gun violence restraining orders based, in part, on a 2016 evaluation of Connecticut’s law. He also points to individual cases where such laws would have made a difference: “The Parkland shooter was making all kinds of public pronouncements,” Wintemute argues. “A gun violence restraining order would’ve allowed his family or law enforcement to go to a judge and get an order that would’ve gotten that gun taken away from him and prevented the shooting.”

Following the barrage of nearly daily shootings, some researchers have begun to call for a community-wide approach, rather than only focusing on high-risk individuals. Charles Branas, an epidemiologist at Columbia University, says that poverty can contribute to gun violence within communities.

In their latest research, Branas and his colleagues examined hundreds of vacant land plots and abandoned buildings in U.S. cities, with a special focus on Philadelphia. These abandoned spaces, like old parking lots and homes, often become places to store illegal firearms. Millions of people live near and walk by these spaces, which can cause community members to feel unsafe or stressed. Using a randomized control design, Branas found that even just planting trees and plants and boarding up windows and doors can make a difference. “Gun violence can be sustainably reduced in poor neighborhoods of those cities by as much as 29 percent,” he says. “These cost peanuts. The return on investment is very high, because shootings are very expensive events.”

For all the progress made in the study of gun violence, gaps still remain. In March, the RAND Corporation released a meta-analysis of thousands of studies published since 2003. The report states that, “Federal funding for research on gun-related mortality is far below levels for other sources of mortality in the United States.” As a result, more research is warranted in virtually all aspects of gun control policy, including on officer-involved shootings, defensive gun use, gun-free zones, the gun industry, and lost or stolen firearms, to name a few.

The latest federal budget, passed by Congress and signed by President Trump in March, may offer some assistance, as it technically allows the CDC to fund research on gun violence. It doesn’t reverse the Dickey Amendment, however, and CDC officials may still face resistance when trying to support such research. In any case, it’s ultimately up to lawmakers, and the public they answer to, to determine how to balance Second Amendment rights with scientific data.

“Hopefully these policy debates have some science behind them,” Hemenway says. “Everything we learn should matter and should have an effect.”

CORRECTION: An earlier version of this piece attributed the lack of protection for domestic violence victims to the 1968 Gun Control Act. It is the later 1994 Violence Against Women Act and the 1996 Lautenberg Amendment that relate to guns and domestic violence.