No Constitution for the Capitol?

I no fan of guns or the NRA, but this is ridiculous and inconsistent. Are citizens of DC not Americans? Are they not guaranteed constitutional rights?

Gun Rights Aren't for District, Judge Rules
By Carol D. Leonnig

"The constitutional right to bear arms doesn't apply to the District of Columbia's residents, a federal judge ruled yesterday in rejecting the claim of several city residents who contended that a 1976 city law banning the possession of guns left them unfairly vulnerable."