CHAIRMAN'S HANCOCK Army Gen. Martin E. Dempsey, chairman of the Joint Chiefs of Staff, signs a baseball for a child during the game between the Washington Nationals and San Fransisco Giants at Nationals Park in Washington, D.C., July, 4, 2015. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 773615-G-GNO12-095.jpg Photo Gallery