A military hearing was abruptly recessed Thursday until commanders decide whether to grant immunity to three officers linked to the drowning of a 19-year-old Iraqi civilian earlier this year.

Lt. Col. Nathan Sassaman, Maj. Robert Gwinner and Capt. Matthew Cunningham already have been punished for their roles in the incident under Article 15, which means there was no court proceeding or public record. Details have not been released, but the Army has said the punishment did not include jail time.

The officers are refusing to testify without immunity at a hearing to determine whether three soldiers should be court-martialed on charges of shoving two Iraqis into the Tigris River (search) north of Baghdad (search) on Jan. 3. Officials say one of the victims drowned.

Maj. Gen. James Thurman, commander of the 4th Infantry Division at Fort Hood, Texas, is deciding whether the officers will be granted immunity, spokesman Lt. Col. Jonathan Withington said. That decision was expected before the hearing resumes Friday.

Sgt. 1st Class Tracy E. Perkins, 33, and Sgt. Reggie Martinez, 24, are charged with involuntary manslaughter, as is 1st Lt. Jack M. Saville, 24, whose hearing will be held later. The third defendant at this week's hearing, Spc. Terry Bowman, 21, is charged with assault for allegedly pushing the surviving victim into the river.

The soldiers are assigned to Fort Carson's 3rd Brigade Combat Team, part of the 4th Infantry.

Once the hearing is complete, the hearing officer will recommend whether the men should face a court-martial. The four soldiers face between 5 1/2 years and 26 1/2 years in prison if they are convicted.

Defense attorneys for the soldiers attacked the prosecution's case at its core Thursday by suggesting no one drowned.

Staff Sgt. Michael Kay testified Thursday that not long after the incident, he saw two Iraqi civilians on the banks of the Tigris and thought they probably were the detainees. His gunner, Spc. Tony Fincher, said the same thing Wednesday.

Family members, however, say Zaidoun Hassoun drowned that night and his body was found down river 13 days later.

The survivor, Marwan Fadel Hassoun, 23, has told The Associated Press he tried to save his cousin's life as soldiers watched and laughed from the bridge above.

An uncle, Nizar Fadhel al-Samarrai, told the AP that Army investigators never showed up to confirm the death of his nephew, though the family was prepared to exhume the body to prove it.

"The investigators told us a forensic doctor would be brought from the United States to conduct an autopsy but this has not happened," he said by telephone from Iraq on Thursday. "They requested a fatwa from local religious authorities to say there's no problem with opening the grave. We got one around seven months ago. But since then there has been no contact from them at all."

Army investigator Sgt. Irene Cintron testified that it was too dangerous to exhume the body, and she relied on the word of family members and members of the Iraqi Civil Defense Force.

Attorneys in the case say troops in Iraq have not been able to locate Marwan Hassoun to get a sworn statement. The hearing officer, Capt. Robert Ayers, agreed to introduce a statement from Marwan Hassoun describing how he and his cousin were forced to jump into the river.

Spc. Rogelio Rubio, who was on patrol during the incident, testified he heard radio chatter that Iraqis would be "dunked" that night and said Perkins was the one who made the threat.

Rubio then began talking about being involved in a similar incident and was immediately interrupted by defense attorneys who said he could be incriminating himself. There has been no mention of a second incident, but the charge sheet says Perkins faces charges for a second assault on Dec. 8, 2003, "on an unknown Iraqi civilian by pushing him into the Tigris River" near Balad.