Keep in mind that this occurred in "gun-free" Maryland and D.C.:

Heavily armed gunmen carried out a series of carjackings and robberies in swift succession in the District and Maryland yesterday afternoon, firing at an off-duty federal police officer in one of the attacks, authorities said.

At least nine robberies and four carjackings unfolded within four or five miles in about two hours: The robbers, some masked, confronted people on busy streets and in an auto-parts store, and they seized several cars after boxing in unsuspecting motorists in traffic, police said.

I'm not saying this couldn't happen in Virginia. But across the river, we're much more likely to shoot back.