“Surveillance video shows the gunman entered the NAVSEA building, at 1336 Isaac Hull Ave., with a shotgun,” wsj,com reports. “He shot a security officer in the head, killing him, and took the officer’s 9 mm pistol and a magazine of ammunition. The shooter then continued through the building and seemed to target his victims, who were mostly on the third and fourth floors.” An armed guard is a sitting duck. Period. The only defense against a bad guy with a gun is a good guy with a gun—that the bad guy doesn’t see coming. Ban gun free zones.