Actually, no. The citizen was an off duty DC cop, so he was allowed to carry the small protective device that enables an individual to effectively stop an attacker. It's OK folks; he was "authorized."
Now, DC Councilman Jim Graham is shocked, SHOCKED, that this attack would happen in such a "prosperous" and "optimistic" neighborhood. I'm sure it would not have been such a "real setback" or "real disappointment" had this happened in a poor neighborhood; one where he's not so "engaged in the issues."
On the side, this would be the second DC police shooting in two days, and this particular incident reminds me of similar ones from last year in which the robbers got copious copper injections from cops.