Sgt. Javal Davis, 27, admitted to stomping on the fingers and toes of a group of seven bound and hooded inmates during an episode of late-night abuse in November 2003. Other guards then undressed the prisoners and stacked them into a naked human pyramid.

In a separate case also heard at the military base in Fort Hood, Texas, military intelligence soldier Spc. Roman Krol pleaded guilty to pouring water on Iraqi prisoners as they crawled naked on the floor and throwing a football at them.

The military judge sentenced him to 10 months in prison, reduced his rank to private and gave him a bad conduct discharge. "I want to apologize to all Americans for the embarrassment I have caused this country," Krol, 23, a Russian immigrant who spoke with a slight accent, told the court.

Davis is one of seven reservists from the Army's 372nd Military Police Company charged with abuses at Abu Ghraib, photos of which caused a worldwide uproar. Two from that unit, including Pfc. Lynndie England, who was pictured holding a leash tethered to a naked prisoner, still face trial.

Several witnesses at another Abu Ghraib trial last month testified about abuses from Davis and Krol at the notorious prison that once served as a torture center under Saddam Hussein.

Davis argues he and other guards roughed up prisoners at the behest of intelligence officials who wanted to extract information from the prisoners.

"Basically, when the intelligence personnel, when they bring them down there, anyone that comes in there with intelligence value, they want to interrogate them and they would ask you to loosen them up," Davis, formerly of Roselle, New Jersey, told ABC News last year.

Under the plea agreement, expected to result in a sentence lower than the original 8 1/2 years he faced, Davis admitted his guilt on three charges: dereliction of duty, making a false official statement, and battery.