Five Blackwater Worldwide security guards have pleaded not guilty to manslaughter charges in the 2007 shooting deaths of 17 Iraqi civilians in Baghdad.
The Blackwater guards were arraigned in front of U.S. District Judge Ricardo M. Urbina on Tuesday.
The not guilty pleas were entered by former Marines Donald Ball of West Valley City, Utah; Dustin Heard of Knoxville, Tenn.; Evan Liberty of Rochester, N.H.; and Army veterans Nick Slatten of Sparta, Tenn., and Paul Slough of Keller, Texas.
Prosecutors said the men unleashed a gruesome attack on unarmed Iraqis, including women and children.
The Blackwater guards contend they opened fire after coming under attack when a car in a State Department convoy they were escorting broke down.