The 633d Security Forces Squadron at Langley Air Force Base, wear a black band over their shield in mourning for Senior Airman Nicholas J. Alden, who was killed en route from Frankfurt International Airport, Frankfurt, Germany, to Afghanistan March 2. The display is a time-honored tradition within the law enforcement community, as a symbolic gesture for officers killed in the line of duty. (U.S. Air Force photo by Airman 1st Class Jason J. Brown/RELEASED)