From The Washington Post:
Robberies have spiked in recent years in the Washington region and many other parts of the country, as the number of juvenile offenders and the availability of guns grows, police officials said. Robberies also are becoming the crime of choice for some former drug dealers, who have switched to stickups after police crackdowns on narcotics trafficking, the officials said.
And here's some blogospheric evidence.
Update: Way to stay on message, Cato. I don't care much about gun control one way or the other -- if I could take them all back, I would, but that seems logistically tricky -- but isn't it possible that the concentration of guns on one end of the stick up is keeping these things robberies rather than murders? Rather than some hyped up, conservative Hill aide fumbling in his coat for his .44 and getting killed, he just gives up his wallet, secure in the knowledge that he can't defend himself. Moreover, since the muggers know the average person isn't carrying a gun, they're probably less likely to shoot when their terrified victim twitches in the wrong direction.