“There are more guns than there are people in the United States.”

In the wake of Monday’s Navy Yard shooting, Eleanor Holmes Norton, D-D.C., addressed national and civic security. Holmes, the nonvoting delegate to Congress representing the District of Columbia, praised the quick police response, but she also noted that no one is entirely insulated from criminal acts.

“We understand that in an open and democratic and free society, you cannot make yourself impenetrable, especially when there are more guns than there are people in the United States today,” she said in a press conference.

Are there really more guns than people? We wanted to dig into the data.

Let’s pin down the easy number: population. The U.S. Census Bureau puts the 2010 population at 308.7 million people. We can get even closer with their nifty population clock, which on the day we checked it estimated a population of nearly 317 million, based on migration, birth and death rates.

Now that we have a frame of reference for Norton’s comparison, let’s move to the question of the number of civilian guns in the country, a murkier subject. As we’ve noted, federally sponsored gun research is scarce.

Most of the available studies are estimates. Since most states don’t register guns or license owners, there’s no concrete thing to count, said Jon Vernick, co-director of the Hopkins Center for Gun Policy and Research.

This June, at President Barack Obama’s request, the Centers for Disease Control and Prevention released a report rounding up what we know about firearm ownership and usage. It offered a 2007 estimate of 294 million guns, but with a pretty hefty caveat:

“Basic information about gun possession, acquisition, and storage is lacking,” the report read. “No single database captures the total number, locations, and types of firearms and firearm owners in the United States.”

The National Rifle Association usually describes the number as “approaching 300 million,” spokesman Andrew Arulanandam wrote in an email.

Daniel van Hoogstraten, Norton’s spokesman, pointed us to a Congressional Research Service study that goes with a slightly higher ballpark: 310 million as of 2009. He made the case that gun proliferation in the country has been increasing at a quick enough rate to exceed the population. While that’s an interesting theory, we found no evidence to back it up.

Since the CRS number is from 2009, the closest apples-to-apples comparison we can make is using the U.S. Census population from 2010. So that’s about 310 million guns to 308.7 million people. Again, we can’t get a firm grip on how much the guns number has changed since then, but the population has gone up by almost nine million, according to the Census estimate.

Our ruling

Norton claimed there are “more guns than there are people in the United States.” There’s no way to know for sure how many guns there are, given the available data. The highest credible guns number we saw was 310 million, which bests the 2010 population by over a million. But it falls short of the 2013 population estimate. We don’t have any reliable gun surveys to approximate 2013 numbers. There’s a chance Norton is right, but the available evidence isn’t definitive. We rate Norton’s claim Half True.