Las Vegas gunman was one of many Americans who own more than 10 guns

When Stephen Paddock opened fire late Sunday night on a Las Vegas outdoor country music festival — killing 59 people and injuring 527 more in one of the deadliest mass shootings in U.S. history — he was reportedly armed with at least 10 guns.

That number may sound staggering — but in the United States, owning that many firearms isn’t so uncommon.

An estimated 7.7 million Americans qualify as gun “super-owners,” meaning they own between eight and 140 firearms, according to the 2015 National Firearms Survey, the results of which will be appearing soon in the Russell Sage Foundation Journal of Social Sciences. These “super-owners” account for just 3 percent of the total adult population in the United States, but their vast collections include half of all guns in the country.

About half of the 55 million American gun owners say they have just one or two firearms, the survey found. About 8 percent have 10 or more. Super-owners, on average, have 17 guns.

It’s not clear how Paddock gathered all of his guns, though the New York Times reports that he legally bought a handgun and two rifles within the past year. A Mesquite, Nevada gun store owner confirmed to VICE News that Paddock was a customer and that the sales were legal.

But “whether he owned all those guns before or not, it’s really, really, really easy to get 10 guns anytime you want,” said lead study author Deborah Azrael, who heads research at the Injury Control Research Center at Harvard’s School of Public Health. “A person who’s not a gun owner can turn into a person who owns 10 guns in as long as them to walk, in many, many places, in as long as it takes them to walk to a store.”

Researchers know relatively little about the impact of owning multiple guns — for example, while scientists know that having a gun in the home increases the risk of suicide, they don’t know how having multiple guns in the home would affect that risk. And not only are there very few surveys focused on just how many Americans own guns — the Centers for Disease Control doesn’t even study gun violence — even less examine how many guns people own.

That makes Azrael’s study, which was conducted in conjunction with Northeastern University researchers, even more unusual and vital.

“We are really hamstrung right now in our understanding of exposure, and we’re hamstrung in all sorts of complicated ways,” Azrael said. “We would be well served to understand in more nuanced ways what needs guns serve for people, what needs are being filled by them. You’d want to know that in terms of being able to have an honest and respectful conversation about any risk posed by guns.”

Ultimately, though, Azrael is less focused on the people who own dozens of guns, and more on the half of all gun owners who have just one or two. The stock of many types of consumer goods is commonly held by a relatively small population, she explained.

Plus, “if you’re thinking, like we do, about harmful exposure to firearms,” she said, “that 50 percent of gun-owning homes is really important to us.”