In 2007, U.S. Army Specialist Jorge G. Sandoval Jr. was charged with murder by the very government he had sworn to serve.

While deployed to the most dangerous area in Iraq known as the "Triangle of Death," Sandoval, an airborne infantryman and elite sniper, was instructed to "take the shot" and kill an enemy insurgent wearing civilian clothes. Two weeks later, Army Criminal Investigation Command descended upon Sandoval's unit and began interrogating the soldiers, trying to link Sandoval and others to war crimes, including murder.

Captain Craig W. Drummond was the...