(CNN) -- Responding to a question at Tuesday's presidential debate that referred to reintroducing the Clinton-era assault weapons ban that expired in 2004, Republican candidate Mitt Romney said that it was already illegal to own those kinds of guns in the United States.
The claim: "Yeah, I'm not in favor of new pieces of legislation on -- on guns and taking guns away or making certain guns illegal. We, of course, don't want to have automatic weapons, and that's already illegal in this country to have automatic weapons," Romney said.
The counterclaim: President Barack Obama did not challenge Romney on the issue, having mainly steered clear of gun rights during the campaign. He said at the debate that he would favor new assault weapons legislation, but conceded, "Frankly, in my home town of Chicago, there's an awful lot of violence and they're not using AK-47s. They're using cheap hand guns."
The facts: Automatic weapons, whether semi-automatic or fully automatic, are legal in much of the country. Semi-automatic weapons account for about 15 percent of the more than 250 million privately owned firearms in the United States, according to the National Rifle Association (NRA).
Fully automatic weapons are legal in most states, but require an extensive federal background check and a permit from the Bureau of Alcohol Tobacco and Firearms, the NRA said.