130916151220-19-navy-yard-shooting-0916-horizontal-large-gallery

Police units walk on a rooftop as they respond to a shooting at the Navy Yard in Washington, DC, September 16, 2013. A shooting rampage at the Washington naval base claimed at least 12 lives including that of an unidentified gunman, city police chief Cathy Lanier told reporters Monday. Lanier said two more potential suspects were still at large after the shooting at the Washington Naval Yard and that the motive of the shooter or shooters was not yet known. “We are confirming 12 fatalities. We had a few additional victims who were injured. They were not fatally injured,” she said, briefing reporters on a street by the base. Lanier gave more details on two male suspects seen near the scene of the shooting, a headquarters building within the riverside base, who police are hunting. AFP PHOTO / Saul LOEB (Photo credit should read SAUL LOEB/AFP/Getty Images)