Staff Sgt. Luke Mefford, 11th Civil Engineer Squadron Explosive Ordnance Disposal training and quality control technician, inspects a patch of discolored dirt with a metal detector June 4, 2015, on Joint Base Andrews, Md. Disturbed or discolored dirt can be a sign of a buried Improvised Explosive Device. (U.S. Air Force photo by Senior Airman Preston Webb/Released)