Updated

A senior military dog-handler testified Wednesday that he was deeply troubled when he and his dog were thrust into the loud, chaotic environment of an interrogation at Abu Ghraib prison in Iraq.

Navy Chief Petty Officer William Kimbro was one of the final prosecution witnesses in the court-martial of another dog-handler, Army Sgt. Michael J. Smith, who is accused of using his dog to harass, threaten and assault detainees from November 2003 to January 2004.

Kimbro recalled being sent into the prison to search cells for explosives. He said the screaming and yelling agitated his dog so much that the dog went after an interrogator, gripping her arm in its mouth. He said he quickly left after one of the interrogators threatened the prisoner with the dog.

"To me, it's a wrong thing to do," Kimbro said. "It's my morals. It's my morals and it's my professional opinion. It's wrong to use your dog in any way that the dog is not trained to do."

Prosecutors rested their case after presenting 18 witnesses over three days, and Smith's attorneys were expected to begin their defense during the afternoon.

Smith's lawyers contend he was following his training and his instructions to help soften up subjects for interrogation. But prosecutors have portrayed him and another Army dog handler, Sgt. Santos A. Cardona, as rogue soldiers who, together with some of the reservists who guarded the prison, tormented prisoners for their own amusement.

Key questions in the case are how dogs were supposed to be used and who authorized the manners in which they were used.

On Monday, Pvt. Ivan L. "Chip" Frederick II, a convicted reservist, testified that Smith and Cardona had told him Col. Thomas M. Pappas, then commander of military intelligence at the prison, approved the use of muzzled dogs for interrogations. But prosecutors say Pappas wasn't authorized to give such an order.

Pappas has been reprimanded and fined for his role in the scandal. He has been granted immunity from prosecution and is expected to be a defense witness.

Smith, 24, from Fort Lauderdale, Fla., is charged with 13 offenses and could serve a maximum penalty of 24 1/2 years in prison.

Cardona, 31, of Fullerton, Calif., is set to stand trial May 22.