Research shows policies that may help prevent mass shootings — and some that don't

The victims of the Uvalde and Buffalo mass shootings were the focus of a candle light vigil in Fairfax, Va.

Allison Bailey/Reuters Connect

Every mass shooting raises calls for better policies. Scientists who study mass shootings say there is evidence suggesting that certain kinds of laws may reduce deaths, but those policy options are not usually discussed in the wake of these events.

Michael Anestis, executive director of the New Jersey Gun Violence Research Center at Rutgers University, says that mass shooting research is a small portion of gun violence research.

Mass shootings account for less than 1% of the 40,000 people killed by guns each year in this country.

The entire field of gun violence research has been neglected and hardly funded, but those researchers who do study gun violence tend to focus on the kinds of violence, like suicide, associated with the most deaths.

There is money out there, but it is not enough to cover the costs of gun violence.

Some studies have found ways to prevent mass shootings.

One study took advantage of the fact that gun laws in the U.S. vary from state to state.

He and some colleagues analyzed more than 30 years of data on shootings in the U.S. that involved four or more victims. They tried to tease out the effect of gun laws.

Despite those limitations, he says, we found two policies that had significant protective effects in lowering the rate of fatal mass shootings.

A requirement that a gun purchaser go through a licensing process was one.

State bans on buying large-capacity magazines for semi-automatic weapons seemed to reduce deaths from mass shootings.

The items allow a shooter to fire many bullets in a short amount of time without interruption. The victims could fight back if the shooter stops and reloads.

Another study shows that this kind of law seems to have a protective effect. David Hemenway, director of the Harvard Injury Control Research Center, worked with colleagues to examine the effect of banning large-capacity magazines on mass shootings.

The states that had bans did better in terms of having fewer mass shootings and the number of people dying from them.

In the wake of a mass shooting, people often argue for the need for comprehensive background checks. He supports that policy, but his research doesn't show that it's linked to a reduction in deadly events.

He says there is a call for policies that make it easier for people to carry guns so they can defend themselves.

While school systems might try to respond to the threat of mass shootings by having police officers on site or having students go through drills, there isn't strong research about those things.

According to data showing that the peak ages for violent offending with firearms is roughly 18 to 21 years old, keeping guns away from young people, whether through safe storage of firearms in a home or age restrictions on purchasing, would be expected to have a protective effect.

The public health risks associated with young people drinking alcohol inspired a ban on drinking under the age of 21. After his 18th birthday, the Uvalde shooter was able to legally buy semiautomatic rifles.

It seems plausible that age restrictions might make it harder for young adults to access weapons capable of creating a mass shooting, but do we have large data-based resources to evaluate those policies? No, we don't.

One emerging policy option that has some preliminary evidence behind it is allowing police officers to temporarily take guns away from people who seem to pose an imminent danger. A study in California that looked at how this process got used over a two-year period found 21 times when it was used in response to threats of a mass shooting.

It is not possible to know if taking away those guns actually prevented mass shootings, but researchers say it is still important data. Guns kill more people than sepsis, a life-threatening response to infections, but funding for gun violence research is less than 1% of that.

There are so many things to study in the gun area, and we have not had enough studies for 25 years.