An on-air stunt involving an empty high-capacity gun magazine brandished by NBC "Meet the Press" host David Gregory last Sunday in the wake of the Newtown, Conn., school shootings has taken a bizarre twist. But it raises important issues about fairness and equality before the law.

After being called out by viewers, the Metropolitan Police Department confirmed that the incident is "under investigation" because it's illegal to even have such a device in one's possession in the District of Columbia, where the show was taped. The law in question is crystal clear: "No person in the District shall possess, sell, or transfer any large capacity ammunition feeding device regardless of whether the device is attached to a firearm." (Emphasis added) Offenses are punishable by up to a year in jail and a $1,000 fine.

There doesn't seem much to investigate. Gregory himself admitted on national television, while he was interviewing Wayne LaPierre, CEO of the National Rifle Association, about gun control, that one of the magazines he displayed held 30 rounds. MPD spokeswoman Gwendolyn Crump confirmed that NBC sought prior permission to use the empty magazine as a prop on the show, but the network's request was properly denied. And what part of "no person" exempts a talk show host from the District's ammo ban?

NBC reportedly contacted the federal Bureau of Alcohol, Tobacco and Firearms and Explosives for a second opinion, and ATF supposedly gave it the green light. But ATF doesn't have jurisdiction over D.C.'s gun laws.

The episode leaves NBC, ATF and the District in a quandary. NBC must explain why the same restrictive gun laws Gregory was advocating for the rest of the nation shouldn't apply to him. Or why, as one disgusted tweeter put it, he should be considered "not guilty by reason of celebrity." ATF must explain why the federal agency with specific jurisdiction over firearms isn't more familiar with gun laws in the nation's capital. And District officials must explain why a well-known broadcast journalist who appeared to knowingly violate the same law used to prosecute other city residents had still not been charged a week later.

NRA president David Keene told CNN on Thursday that Gregory should not be prosecuted for what he termed "a silly felony." But if D.C. doesn't prosecute Gregory for possession of an assault rifle magazine, how in all fairness can it charge anybody else with the same offense?