WASHINGTON -- The Metropolitan Police Department said Wednesday that it had opened an investigation into whether NBC and David Gregory, the host of "Meet the Press," broke the law when Mr. Gregory displayed a high-capacity gun magazine during an interview Sunday with the vice president of the National Rifle Association.
NBC had asked the police for permission to use a high-capacity magazine and "was informed that possession of a high-capacity magazine is not permissible, and their request was denied," said Officer Araz Alali, a police spokesman.
"This matter is currently being investigated," he said. "I can't get into any other specifics of this investigation."
It was not clear how or where Mr. Gregory obtained the magazine, and an NBC News spokeswoman declined to comment Wednesday. "Meet the Press" is generally taped in Washington.
According to a federal law enforcement official, an NBC employee contacted the Bureau of Alcohol, Tobacco, Firearms and Explosives on Friday to ask whether it would be legal for Mr. Gregory to show the magazine on television without the ammunition. The bureau, which does not enforce Washington's gun laws, said it would be legal. That information, however, was incorrect, as it is illegal to have any empty magazine in Washington, the official said.
Mr. Gregory displayed the magazine, which rapidly feeds ammunition into the chamber of a gun, about 10 minutes into his interview with NRA Vice President Wayne LaPierre. The host picked it up from the table in front of him and held it in the air as he questioned Mr. LaPierre.
"Let's widen the argument out a little bit," Mr. Gregory said. "So here is a magazine for ammunition that carries 30 bullets. Now, isn't it possible that, if we got rid of these, if we replaced them and said, 'Well, you could only have a magazine that carries five bullets or 10 bullets,' isn't it just possible that we can reduce the carnage in a situation like Newtown?"
Mr. LaPierre said he did not believe that it would have made a difference. "There are so many different ways to evade that, even if you had that," he said.
Gun laws in the nation's capital generally restrict the possession of high-capacity magazines, regardless of whether the device is attached to a firearm.
People in Washington who are caught in possession of the type of magazine that Mr. Gregory had can face up to a year in prison, said criminal defense lawyer David Benowitz. "You would be arrested; you would most likely be charged with possession of an illegal magazine," he said, adding that "depending on what time you were arrested, you would most likely be held overnight."
Prosecutors and defense lawyers often work out a plea agreement in which defendants receive probation and have a misdemeanor charge on their criminal record, Mr. Benowitz said. If defendants have a prior criminal record or lose a jury trial, they could face a stiffer sentence.
Associated Press contributed.