As cities across the country reel from multiple shooting massacres in just the last few weeks, activists, politicians and others are calling on the federal government to do something about gun violence.

The measure that seems to have the most support is universal background checks, but many are hoping that something that used to exist in the United States can be renewed: the assault weapons ban.

Back in 1994, Democrats like then-Rep. Chuck Schumer (D-NY) and Sen. Dianne Feinsten (D-CA) included a prohibition on the production and sale of some assault weapons as well as high capacity magazines in a sweeping crime bill signed into law by former President Bill Clinton.

The ban had a “sunset” provision built in that effectively ended the decade-long experiment, but it’s worth looking at whether the ban worked.

That’s a difficult question to answer.

For more than 20 years, Congress has included a provision in funding bills that prohibits the Centers for Disease Control and Prevention from using money to do anything that could be considered advocating for or promoting gun control.

But some studies were funded by the National Institute of Justice to try to figure out what the impact of the assault weapons ban was. A key investigator conducting those studies was Dr. Christopher Koper, the principal fellow of George Mason’s Center for Evidence-Based Crime Policy. In the 2013 book Reducing Gun Violence in America, Koper wrote “In summary, the ban had mixed effects in reducing crimes with the banned weaponry because of various exemptions and loopholes in the legislation. The ban did not appear to affect gun crime during the time it was in effect, but some evidence suggests it may have modestly reduced gunshot victimization had it remained in place for a longer period.”

And in 2017, he and other researchers had a slightly more positive view of the ban’s impact while it was in place. The study cautions that much more research is needed, but that

“it provides further evidence that the federal ban curbed the spread of high capacity semiautomatic weapons when it was in place and, in so doing, may have had preventative effects on gunshot victimizations.”

Dr. John Tures, a political science professor at LaGrange College, has drawn conclusions that are a bit more definitive. He also thinks that the uptick in mass shootings since the ban ended provides evidence that the ban was successful. But he used data gathered not by the U.S. government, but liberal publication Mother Jones, to get there.

The magazine has attempted to compile all mass shootings from 1982 to 2019, but not all of those shootings are attributable to assault weapons.That’s a limitation in Tures’ analysis, but according to his breakdown of the data there were 9.2 deaths per year in mass shootings in the 10 years that the ban was in effect. In the years since, the rate has gone up to 43.6 deaths per year, he says.

“In all the cases, the years with the highest numbers of shootings were 2017 and 2018. If you do a study that looks just before the ban and after the ban, the ban reduced things slightly and that's something I would agree with Koper.” But he added that the strongest evidence the ban was working is seen in comparing the years the ban was in effect to 2005, when it expired, to today.

Franklin Zimring, the faculty director for criminal justice studies at the University of California, Berkeley School of Law, cautioned that while mass shootings have gone up in those years, “there was no clear before and after reduction in body count from assault weapons- specific events.”

But he offered another way to look at it.

“One of the things that you can find out is whether [the banned assault weapons] — that the extent to which they were introduced during that period, did it go down? And the answer is, ‘yes it did.’ So in that sense, if the weapons were the problem, the legislation had impact on that problem, ” Zimring said.