Tech. Sgt. Ollie Bradley, 36th Security Forces Squadron flight chief, demonstrates how to do a walk and turn sobriety test Jan. 13, 2016, at Andersen Air Force Base, Guam. The walk and turn challenges an individual's short term memory, balance and motor skills which are needed for safe operation of a vehicle. (U.S. Air Force photo/ Airman 1st Class Jacob Skovo)