Observer
U.S. Air Force Staff Sgt. Gwendolyn Parks (left), a Drug Demand Reduction Program observer, and Senior Airman Mariana Delgado-Perez (right), 824th Base Defense Squadron flight trainer, ensure a specimen container has not been tampered with June 26, 2013, at Moody Air Force Base, Ga. The DDRP takes this measure to ensure the reliability of test results. (U.S. Air Force photo by Sandra L. Marrero/Released)