Frederick, who like Graner worked as a prison guard before being sent to Iraq with the 372nd Military Police Company, an Army Reserve unit, said that in his civilian job "I learned to treat inmates with respect."
But that all changed, he said, when they arrived at Abu Ghraib, a rundown facility where Saddam Hussein's regime reportedly engaged in torture. "There were cold cells, no ventilation, no lights, no toilets, no running water, nudity and handcuffing of prisoners to the doors," Frederick said.
Describing the night Graner punched the prisoner in the side of the head, Frederick rated the force of the blow at "about an eight or a nine" on a 10-point scale. Graner, he said, "shook his hand and said, 'Damn, that hurt!' "
Frederick acknowledged that he hit the other inmate in the chest, and said his punch was "about a seven or an eight." He said the detainee "kind of sat down on his knees. It knocked the wind out of him."
Frederick said none of the prisoners posed a threat, and none of the soldiers were afraid of them.
Like Sivits, Frederick compared the abuse to a night of male revelry. He said Graner was "pretty normal and carrying on."
Frederick said he never saw a list of approved torture techniques for prisoners, but that "we were given orders to punish them for talking" and other offenses. Guards often deprived inmates of food and sleep and handcuffed them to doors -- "things like that," Frederick said.
But "things" went further, Frederick said. He engaged in sexual foreplay with a teenage prostitute detained at Abu Ghraib and photographed her exposing her breasts. Guards forced male inmates to perform mock oral sex on one another.
Once, Frederick said, an intelligence officer told him to make a high-value prisoner undergo a rigorous routine of physical exercise to wear him down. "I don't care what you do," Frederick said the officer instructed. "Just don't kill him."
A third soldier who pleaded guilty, Megan Ambuhl, also testified against Graner. She received no prison time but was demoted in rank from specialist to private and was separated from the Army.
Ambuhl said that Graner came up with the idea of using a leather leash to yank a naked prisoner from his cell, and that Graner gave the leash to his girlfriend, Pvt. Lynndie R. England, to pull the man by his neck while Graner photographed her.
England, who recently gave birth to Graner's son, is awaiting a decision on whether she will be court-martialed.
A fourth convicted soldier, Pvt. Armin J. Cruz, who worked as an interrogator and was sentenced to eight months in prison, was not called to testify.
Two other soldiers, Sgt. Javal S. Davis and Spc. Sabrina Harman, are scheduled for trial next month.