Tapes obtained by CNN of interrogations of a group of U.S. servicemen charged with unprovoked killings of Afghan civilians describe gruesome scenes of cold-blooded murder.

"So we met this guy by his compound, so Gibbs walked him out, set him in place, was like standing here," says Cpl. Jeremy Morlock, detailing how, on patrol earlier this year and under the command of his sergeant, Calvin R. Gibbs, he and others took an Afghan man from his home and killed him.