Updated

A key prosecution witness in the prison abuse trial of an Army dog handler testified the defendant acted properly when he let his animal bite a detainee at the Abu Ghraib prison in Iraq.

Former Staff Sgt. Ivan L. "Chip" Frederick II was a key government witness Tuesday in the court-martial of Sgt. Santos A. Cardona. Prosecutors have portrayed Cardona as part of a small crew of corrupt soldiers who enjoyed tormenting detainees. The court-martial continues Wednesday.

In testimony augmented by photographs, Frederick said he saw Cardona's Belgian shepherd, Duco, bite detainee Mohammed Bollendia twice after the prisoner attacked former Cpl. Charles A. Graner Jr. in a prison hallway.

"I've thought about it and thought about it and, my opinion, I thought it was justified," Frederick said in response to a written question from one of the jurors.

Frederick and Graner are serving prison terms for their leading roles in the Abu Ghraib scandal.

Frederick said military police had taken Bollendia from his cell to search it for weapons. Cardona and another dog handler, Sgt. Michael Smith, had their animals bark at Bollendia when he refused to lie on the hallway floor, Frederick testified.

"He was acting really scared," Frederick said.

After the prisoner jumped on Graner, striking him with his hands, Cardona told Graner to push Bollendia away and then released his dog, which bit the prisoner's right leg, grazing the skin, Frederick said. Bollendia again jumped on Graner and Cardona again released the dog, which bit the prisoner's left leg deep enough to draw blood, Frederick said.

Frederick, now a private serving an eight-year sentence for his role in the scandal, said the MPs probably could have subdued Bollendia without the dogs but that he believes the canines were used properly.

Frederick also testified Cardona said he and Smith were having a contest to see how many detainees they could make urinate on themselves.

Smith, of Fort Lauderdale, Fla., was convicted at a court-martial in March of maltreatment, conspiracy, dereliction and an indecent act. He was sentenced to 179 days in prison.

Cardona, 32, of Fullerton, Calif., is charged with assault, dereliction of duty, maltreatment of detainees, conspiracy to maltreat detainees and lying to investigators in late 2003 and early 2004. He faces up to 16 1/2 years in prison if convicted on all counts.

Ten low-ranking soldiers have been convicted of abusing prisoners at Abu Ghraib, in many cases by forcing them to assume painful or sexually humiliating positions while being photographed.