Ryan Salmon fires an assault rifle at the Lynchburg Arms & Indoor Shooting Range in Lynchburg, Va., on Oct. 20, 2017.

Last week's horrific massacre of 14 students and three staff members in Parkland, Fla., has reinvigorated the national debate over assault weapons. A Quinnipiac poll released Tuesday, for instance, found that 67 percent of Americans, including 53 percent of gun owners, say they favor such a ban — the highest level of support seen on this question since 20 children and six educators were murdered at Sandy Hook Elementary School in 2012.

Critics of bans on assault weapons, however, say they do little to save lives. The NRA correctly points out that assault weapons are used only in a tiny fraction of gun crimes. The gun rights group also notes that a federally funded study of the previous assault weapons ban, which was in place from 1994 to 2004, concluded that “the ban’s impact on gun violence is likely to be small at best, and perhaps too small for reliable measurement.” Similar points have been made in arguments against a new ban in publications running the ideological gamut from Breitbart to the New York Times to HuffPost.

But the 1994 assault weapons ban was never intended to be a comprehensive fix for “gun violence” writ large. Its purpose, according to gun violence experts and the lawmakers who wrote the bill, was to reduce the frequency and lethality of mass shootings like the ones in Parkland, Sandy Hook and elsewhere. And on that front, the data shows it had a significant impact.

Louis Klarevas, a researcher at the University of Massachusetts at Boston who wrote a book on mass shooting violence published in 2016, says that the impetus for a federal assault weapons ban came in 1989. That year Sen. Howard Metzenbaum, an Ohio Democrat, introduced the original assault weapons ban bill after a gunman armed with an assault rifle killed five children and injured 29 more in a schoolyard in Stockton, Calif.

“The guy used an AK-47 variant, with large capacity magazines” capable of holding 10 or more rounds, Klarevas said. The shooting “got a lot of attention” and galvanized public opinion. National polls conducted in the months following, for instance, showed that over 70 percent of Americans supported bans on assault weapons like the one used in Stockton.

But Metzenbaum's bill didn't pass, and Congress spent several years debating other assault weapons measures that were less stringent in nature. None of those were ever signed into law.

Momentum returned with two back-to-back mass shootings in 1993: one at a San Francisco law firm that killed eight people and injured six more, and another on a Long Island Railroad train that left five dead and 19 wounded. Sen. Dianne Feinstein of California, architect of the 1994 assault weapons ban, said that “it was the 1993 mass shooting at 101 California Street in San Francisco that was the tipping point for me. That’s what really motivated me to push for a ban on assault weapons.”

The San Francisco shooting “made clear that the increasing sophistication of weapons had made it possible for a mass shooter to murder large numbers of people in a matter of minutes,” Feinstein said. “The goal of the ban was to reduce the frequency and deadliness of mass shootings.”

The final piece of legislation that we now know as the federal assault weapons ban was signed into law a little over one year after the San Francisco shooting.

The 1994 law included a ban on 18 specific models of assault weapons, as well as a ban on any firearms containing certain military-style features, like a bayonet mount, a flash suppressor or a folding stock. It also banned high-capacity magazines capable of holding more than 10 bullets. The bill allowed individuals already in possession of such weapons to keep them. It was also set to expire after 10 years' time.

“The original intent of the assault weapons ban was to reduce the carnage of mass shootings,” Klarevas said. “And on that front the data indicate that it worked.”


Klarevas has compiled data on gun massacres involving six or more fatalities for the 50 years before 2016. His numbers show that gun massacres fell significantly during the time the assault weapons ban was in place, and skyrocketed after the ban lapsed in 2004. A separate mass shooting database compiled by Mother Jones magazine shows a similar trend.

Klarevas wasn't surprised by the 2004 report showing the ban had little effect on overall rates of gun crime. “If there was going to be any benefit on [overall] violent crime, that would have been a pleasant surprise,” he said. But, “the real objective of the assault weapons ban was always to reduce both the frequency and lethality of mass shootings.”

Klarevas is particularly concerned about what the numbers show for the years after Congress allowed the assault weapons ban to lapse. Guns like the ones used in Parkland and in other mass shootings are now among the most popular firearms currently on the market. The proliferation of these guns means that would-be mass shooters have little trouble obtaining them.

“In the last three years we have had as many gun massacres with assault weapons as in the decade prior,” Klarevas said. “The trend is continuing to escalate.”