DEFENSE LEADERS Defense Secretary Chuck Hagel, center, and Army Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, walk with Navy Adm. James A. Winnefeld Jr., far left, vice chairman of the Joint Chiefs of Staff, Navy Secretary Ray Mabus, and Navy Adm. Jonathan W. Greenert, chief of naval operations, to honor the 12 victims of the Washington Navy Yard shooting during a ceremony at the Navy Memorial in Washington, D.C., Sept. 17, 2013. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 397629-V-MPC15-130.jpg Photo Gallery