Tech. Sgt. Joel Meyer and Senior Airman Jacob Lacefield participate in a threat scenario during training. U.S. Air Force Tech. Sgt. Joel Meyer (top) and Senior Airman Jacob Lacefield, both with the 28th Security Forces Squadron, participate in a threat scenario during training at Ellsworth Air Force Base, S.D., on April 5, 2010. SHARE: Download: Full Size (0.03 MB) Credit: VIRIN: 268379-W-BOS89-244.jpg Photo Gallery