Berlin—On Tuesday, federal prosecutors in New York brought charges against Arid Uka, a radical Islamist who killed two U.S. servicemen and wounded two more in Germany’s Frankfurt International Airport in March.

Uka, who was born in Kosovo, worked as a postal employee at the airport, is reported to have shouted “Allahu akbar!” (Arabic for “God is great”) as he shot U.S. airmen Zachary R. Cuddeback, 21, of Stanardsville, Virginia, and Nicholas J. Alden, 25, of Williamston, South Carolina, who were on their way to Afghanistan.