The District will not charge the host of NBC's "Meet the Press" with a crime for brandishing a high-capacity magazine as a prop during a December interview with a National Rifle Association official.

D.C. authorities spent several weeks investigating David Gregory's actions, but the city's attorney general announced Friday that he would not file charges against the journalist, who could have faced up to a year in jail if convicted of a crime.

In a letter to NBC's lawyer, Irvin Nathan said his office had "determined to exercise its prosecutorial discretion to decline to bring criminal charges against Mr. Gregory" despite "the gravity of the illegal conduct in this matter."

High-capacity ammunition magazines are banned in the District, where the show is filmed.

But Nathan warned that the "decision not to press charges in this matter was a very close decision" and said that his office would pursue any future violations of the District's strict gun laws by Gregory or other NBC employees.

In his three-page letter, Nathan said his office's decision was affected by "our recognition that the intent of the temporary possession and short display of the magazine was to promote the First Amendment purpose of informing an ongoing public debate about firearms policy in the United States."

Nathan did accuse NBC, though, of mounting "feeble and unsatisfactory" efforts to determine whether using the magazine as a prop would be legal under District law.

"Although there appears to have been some misinformation provided initially, NBC was clearly and timely advised by [a police] employee that its plans to exhibit on the broadcast a high capacity-magazine would violate D.C. law, and there was no contrary advice from any federal official," Nathan said.

"Meet The Press" executives said in a statement that the show would heed Nathan's warning after the incident, which stemmed from a contentious interview with Wayne LaPierre, the executive vice president of the NRA. During the interview, shortly after the massacre at Sandy Hook Elementary School in Newtown, Conn., Gregory displayed what he described as a 30-round magazine.

"We displayed the empty magazine solely for journalistic purposes to help illustrate an important issue for our viewers," the statement said. "We accept the District of Columbia attorney general's admonishment, respect his decision and will have no further comment on this matter."