The jury of four Army officers and six senior enlisted men was to begin deliberating Friday.
Graner's lawyers had indicated earlier that Graner would probably be the final witness, and that he would offer his version of what occurred.
But Guy Womack, his lead lawyer, said the other defense witnesses provided all of the evidence necessary to make the case that military and civilian intelligence agents controlled Abu Ghraib and ordered Graner to soften up detainees for questioning.
"We came in with a checklist of things we wanted to present to the jury," Womack said. "Once we accomplished that, there was no reason to continue."
Graner, a 36-year-old reservist from Uniontown, Pa., is the first soldier to be tried on charges arising from the Abu Ghraib scandal. He had appeared glum in recent days, but outside court he said: "I feel fantastic. I'm still smiling."