A paratrooper scans the iris of another using a Handheld Interagency Identity Detection Equipment, or HIIDE, system during training Jan. 10, 2012, at the Joint Readiness Training Center, Fort Polk, La. The device measures personal biometric data that allow friendly forces to identify persons of interest at a later date. (U.S. Army photo by Sgt. Michael J. MacLeod) (Photo by U.S. Army)