Arid Uka, a Kosovan Muslim, nicknamed Abu Reyann, was be behind the fatal shooting of two U.S. airmen at Frankfurt airport. Obama Says U.S. Will Spare No Efforts in Investigating Killings. 21-year old Arid Uka, a Kosovo Muslim gunman, shouting “Allahu Akbar” opened fire on a bus carrying U.S. airmen in Frankfurt, Germany, killing two and wounding two others before his gun jammed and he...