Human Rights Watch said it had spoken with a third sergeant and two Army physician's assistants who can back up the claims of brutality. But they said those individuals had not given permission to release their stories.
For now, Fishback has been instructed to remain at Ft. Bragg, where he must obtain a pass for any trips off the base farther than 50 miles.
When he came to Washington to meet with the committee two weeks ago, he came with a pass. But according to Human Rights Watch, the Army learned of that session and denied his request for a pass to return to Washington.
The Army would not discuss those matters. But Paul Boyce, a spokesman, said, "The Army does not tolerate detainee abuse."
He added that it had conducted more than 400 investigations and 2,800 interviews on possible abuse since the Sept. 11, 2001, terrorist attacks. He said 230 members of the Army had been punished.
Central to Fishback's reasoning in pursuing the abuse matter is the "Cadet Honor Code" he studied before graduating from West Point in 2001. It says, "A cadet shall not lie, cheat, steal, or tolerate those who do."
In his personal chronology, he wrote, "Bottom line: I am concerned that the Army is deliberately misleading the American people about detainee treatment within our custody."
When the prison abuse scandals at the Abu Ghraib prison erupted in April 2004, he noted that he had heard of instances around Fallouja that were "even more intense."
By June of this year, his concern had grown because it had become clear that the military was holding few soldiers accountable for Abu Ghraib beyond the half-dozen guards arrested, and that none of their superiors had been court-martialed. He asked the Army's inspector general at Ft. Bragg for an analysis of the Geneva Convention on treatment of prisoners.
"He listens to me and agrees to give me an IG investigation summary," Fishback wrote. "It is very incomplete and provides no information that I need."
He called the International Committee of the Red Cross for an interpretation of the Geneva Convention, and found it "much closer to my West Point education."
Then he learned of two new incidents of abuse: Someone had "interrogated" a detainee to death in Iraq and "fed a prisoner water by saturating the sand bag over the prisoner's head."
That was enough for him, he wrote. He began "obtaining documents and additional points of view from fellow officers and determining possible courses of action."
That road led him outside the Army.