After alleged gunman Jarrod Ramos killed five people in a mass shooting at the Capital Gazette's newsroom in Annapolis, public calls for stricter gun laws are becoming louder in the United States.

Australia has witnessed one mass shooting since 1996 — the same year the country passed a sweeping set of gun regulations.

Researchers say similar policies could work in the US, especially if laws were instituted at the national level.

Australia has had one mass shooting since 1996.

Meanwhile, the United States has suffered 154 mass shootings (in which four or more people were killed by a lone shooter) in just the last six months. For perspective, we are 178 days into the year, which means the US has had nearly as many mass shootings as days in 2018.

The latest shooting — when Jarrod Ramos allegedly killed five people and "gravely injured" several others at the Capital Gazette's newsroom in Annapolis — has once again renewed a national debate around stricter gun regulation.

We might look to other countries to see whether tighter gun laws can be successful. That is the case in Australia, where the government passed the National Firearm Agreement (NFA), a sweeping set of gun regulations, in 1996. According to the most recent data available — from 1996 to 2015 — the annual number of gun-related homicides decreased from 516 to 211.

Before 1996, the country had seen 14 mass shootings, but one particularly horrific spree led to gun reform. In April 1996 — in the worst mass murder in Australia's history — gunman Martin Bryant killed 35 people and injured 24 others at a seaside resort in Port Arthur, Tasmania. Twelve days later, the government instituted the NFA, which includes three main provisions: tight control on semi-automatic and fully automatic weapons; a national registry of firearm owners; and a buyback program so that Australians could sell guns back to the government.

While it's difficult to say whether the NFA directly led to the drop in mass shootings and a reduction in gun-related homicides, experts say we can draw some links.

Bipartisan research suggests that Australia's strict gun regulations have led to a big decline in firearm homicides

One of the more recent studies on the subject is by Elena Andreyeva and Benjamin Ukert, two public health researchers at the University of Pennsylvania. Their 2017 working paper suggests the NFA decreased firearm mortality by 60%, including homicides and suicides. Another one of their peer-reviewed studies, published in 2017, came to a similar conclusion.

"The NFA is unique in that it tackles many different problems at the same time," Ukert told Business Insider.

The newer study compares gun deaths in various Australian states before and after the NFA. It suggests the NFA was more successful in states with higher rates of firearm deaths before gun regulations were instituted.

Andreyeva and Ukert controlled for several variables, including gender, age, economic status, and previous gun laws. Though their study accounts for both firearm homicides and suicides, they did not see a substantial decrease in total suicide rates since the NFA. The regulations may have had a much larger effect on homicides, however. The study estimates that, on average in Australian states, there has been a 96% reduction in murders by guns since the NFA.

Other research has come to similar conclusions. A 2016 paper from the University of Sydney and Macquarie University suggests that Australian gun policies correlated strongly with declines in firearm homicides. They acknowledge that there are other factors at play (including improvements in medical technology and an overall improvement in crime), but also say the NFA was at least partly responsible for the national reduction in firearm deaths.

What the US can learn from Australian gun control

Andreyeva and Ukert add that, based on their research, the US can learn a few things from Australian gun regulation.

For example, the NFA mandates that Australians must wait 28 days before they can buy a gun, due to rigorous background checks.

"If it's hard to buy guns legally, in crimes driven by passion as opposed to preplanned acts, [the regulation] would have a larger effect," Andreyeva said. "If I want to commit a mass shooting and I come to the store to buy a gun, but I'm told I have to wait 28 days, I might change my mind completely."

Mick Roelandts, firearms reform project manager for the New South Wales Police, looks at a pile of about 4,500 prohibited firearms in Sydney that have been handed in over the past month under the Australian government's buyback scheme, July 28, 1997. David Gray/Reuters

Unlike American gun regulations, the NFA also applies to every Australian state. Prospective gun owners must obtain a permit and license, be at least 18, undergo a firearms safety training, provide a "genuine reason" for buying a gun other than personal protection, and provide documentation about storage arrangements for their weapon.

American gun culture differs from Australian gun culture

That said, there are differences between gun culture in Australia and America, which could make something like the NFA less effective in the US.

Gun control is politically polarizing in the US, and firearms are very accessible. (Currently, the number of registered gun stores outnumber Starbucks and McDonald's locations in many US cities, making firearms a deep-rooted part of American life.)

Gun control is a debate in Australia, but not nearly to the same degree. Since the NFA was passed, both of the country's two major political parties (the Labor Party and the National Coalition) have expressed support for it, and any changes to the law require a unanimous vote.

The public also readily gave up a large number of their guns after the 1996 shooting. During the NFA's buyback program in 1997, Australians sold 700,000 firearms to the government, reducing the number of civilian guns by approximately 20%. And in September of 2017, the Australian government collected 26,000 more unregistered firearms. Of course, the data does not account for every firearm in the country, like those bought on the black market.

Andreyeva and Ukert believe that the NFA made the black market for guns smaller in Australia, since an ocean surrounds the country and makes it more difficult to import guns illegally. Even if individual US states imposed strict gun control, firearms could still easily flow in from other states or nearby countries.

"The states would probably need to come together, and the regulations would need to be at the federal level," Ukert said.