UNITED STATES - JULY 24: U.S. Capitol Police Officer Gene Petty stands on ceremonial duty before an annual wreath-laying ceremony for U.S. Capitol Police Officer Jacob J. Chestnut and Detective John M. Gibson, killed by a gunman while on duty in 1998. The ceremony took place at an entrance to the Capitol dedicated to the slain officers. (Photo By Chris Maddaloni/CQ Roll Call) 2012