In the wake of the deadliest mass shooting in U.S. history, the Senate failed to pass four bills to shore up background checks, despite public support for the measures hovering around 90 percent. The status quo is deeply unpopular, but it remains the law.

The American mass shooting experience, which tends to follow a predictable cycle of tragedy -> outrage -> finger-pointing -> inaction, stands in sharp contrast to what happened in Australia in 1996. There, a horrified country came together to pass a sweeping gun reform package after a man used an assault rifle to murder 35 people and wound 19 others.

Australia's National Firearms Agreement (NFA) most famously included a ban and mandatory buyback of semiautomatic assault rifles like the one used in the mass shooting (also, it's worth pointing out, like the ones used in seven of the past eight public mass shootings here in the United States). Authorities purchased and destroyed more than 650,000 newly outlawed guns by 2001 and collected nearly 70,000 handguns during a second buyback in 2003.

From a policy standpoint, the question is whether this massive effort made the country any safer, or whether it just represented a costly infringement on Australian gun owners' liberties. New research published in the Journal of the American Medical Association offers the most complete look yet at the impacts of Australia's NFA, and offers some lessons for the American experience.

Much of the paper is a confirmation, using more complete data, of what previous research has found. Here are the important things you should know.

1. Australia hasn't had a single mass shooting since the gun buyback.

The analysis, by Simon Chapman at the University of Sydney and colleagues, found that there were 13 mass shootings in the 17 years prior to the passage of the National Firearms Agreement. Since then, there hasn't been a single one.

Chapman and his colleagues define mass shooting as five or more victims shot and killed, not including the shooter. In the United States, there have been 11 mass shootings meeting that definition this year alone, and 33 since 2014.

Chapman, it's important to note, was active in the push for gun control in Australia following the 1996 massacre, and has written a book about the experience. Still, his paper is very cautiously worded -- at no point does he claim that the gun ban caused any of the observed changes.

In an editorial accompanying Chapman's research, Daniel Webster, director of the Johns Hopkins Center for Gun Policy and Research, expresses more certainty. He notes that it is "difficult to pinpoint precisely which aspect of the policy contributed to this success," but he adds, the substantial reduction in the population’s exposure to semiautomatic long guns capable of accepting large-capacity magazines (LCMs) for ammunition is likely to have been key."

These assault rifles have become very popular among American gun owners in recent years. The NRA estimates that the number of these rifles in circulation runs into the millions. Webster points to research showing that, as the rifles have become more popular, "the mean number per month of victims of mass shootings with assault weapons or pistols with LCMs has increased more than 3-fold (1.1 to 3.8)" since the expiration of our own assault weapons ban in 2004.

2. There was no statistically significant change in firearm homicides after the gun ban.

Chapman found that homicides by firearm fell more rapidly after the passage of Australia's National Firearms Act: Those were falling by about 3 percent per year before the NFA, and the decline accelerated to 5.5 percent per year after.

However, non-firearm homicides showed the same pattern too, according to Chapman's analysis. According to the paper, the change in homicide rates before and after the NFA is not statistically significant. And it isn't possible to determine whether the falling rates are attributable to the Firearms Act or to some other factor.

However, Hopkins's Webster points out that similar patterns haven't been observed in other countries. "Had Australia not implemented the 1996 NFA and its firearm homicide trends changed in ways similar to what occurred in neighboring New Zealand, the United States, or Canada beginning in 1997, Australia may have experienced a much slower rate of decline followed by a plateau or increase in firearm homicide rates." But it's impossible to know for sure.

3. Suicide rates did start to fall after the NFA.

Suicides show a more striking pattern. Suicides, by all methods, were actually rising before the passage of the NFA. Afterward, the suicide rate began to fall. While this change was statistically significant, it's still not possible to say for sure whether the change was directly caused by the NFA or by something else.

4. People weren't simply using other weapons as a result of the ban.

"The data in this study show that the declining rate of suicide by firearm accelerated significantly after the 1996 gun laws, with no apparent substitution to other lethal methods, or if there was substitution, it may have been into less lethal methods," Chapman and his colleagues write. Non-firearm suicides and homicides have both been falling since the passage of the NFA. And overall rates of suicide and homicide are down too.

Overall, Chapman's research shows that Australia has become a less violent place since the passage of the National Firearms Act. While his analysis can't say whether the act directly caused these outcomes, Webster believes that American readers should take note:

"The experience in Australia over the past two decades since enactment of the NFA provides a useful example of how a nation can come together to forge lifesaving policies despite political and cultural divides."

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