Sivits, the first soldier scheduled to be court-martialed in the abuse scandal, was expected to plead guilty next Wednesday in Baghdad. He has cooperated with prosecutors and faces lesser charges than his colleagues.
He said the mistreatment was not authorized by higher-ups in the chain of command. "Our command would have slammed us," he said. "They believe in doing the right thing. If they saw what was going on, there would have been hell to pay."
On Friday, the U.S. Army announced it has filed criminal charges including adultery against Military Police Cpl. Charles A. Graner who figures prominently in Sivits' account.
Brig. Gen. Mark Kimmitt said other charges against Graner also included conspiracy to maltreat detainee, dereliction of duty, cruelty and maltreatment of detainees. He will be arraigned May 20 but no trial date has been set, Kimmitt added.
Sivits' statements are the most in-depth descriptions of the abuse by a defendant to have been made public. Lawyers for the soldiers that Sivits named said his statements were "fabricated" and questionable because of his plea deal.
In one instance, a prisoner handcuffed to a bed with bullet wounds in his legs screamed "Mister, mister, please stop," as Graner struck him with a police baton, according to statements Sivits made to military investigators.
"I was laughing at some of the stuff that they had them do," Sivits told investigators in January. "I was disgusted at some of the stuff as well."
Transcripts of Sivits' statements were provided to the Washington Post the New York Times and the Los Angeles Times.
Seven soldiers have so far been accused of abusing prisoners. Spc. Megan M. Ambuhl was the only GI who Sivits did not accuse of wrongdoing in the statements.
In other developments in the prisoner abuse scandal:
The coalition periodically releases prisoners from Abu Ghraib, the notorious Saddam-era jail on the western outskirts of Baghdad where abuses of prisoners by American soldiers have erupted into a major scandal and damaged the credibility of the U.S.-led coalition governing Iraq.
Rumsfeld called the controversy surrounding the prison a "body blow for all of us" and said the people who did wrong will be punished.
Rumsfeld fiercely defended the Pentagon's response to the abuse revelations.
"The garbage that you keep reading — about cover-up and the Pentagon doing something to keep some information from people — is unfair, inaccurate and wrong," he said. "And if I find any evidence that it's true, I'll stop it."
Rumsfeld also predicted that the abuse scandal would get worse in the days ahead.
"More bad things will come out, unquestionably," he said without being specific. "And time will settle over this and we'll be able to make an assessment of what the effect has been" on the effort to stabilize Iraq. "It clearly has not been helpful. It has been unhelpful."
Among his first responses to the international outcry over the abuse photos, Rumsfeld sent Vice Adm. Albert T. Church, the Navy's top investigative officer, to the Guantanamo prison camp last week. Church, who accompanied Rumsfeld on his trip to Iraq, told reporters that he found no major problems at that prison.
Church found eight violations. Four were violations by military police soldiers who guard the detainees at Guantanamo, three were violations by interrogators and one was a barber who gave a detainee an "unauthorized haircut" - a Mohawk-style cut that Church said amounted to humiliating the prisoner.
One of the violators, who punched a detainee in handcuffs, was punished by having his rank reduced, Church said.
Church said he felt confident in saying there currently are no major lapses in the humane treatment of Guantanamo prisoners, but he added that he could not be 100 percent sure because he took sworn testimony from only 43 people there, in addition to reviewing medical records of 100 detainees.
The New York Times reported Thursday that CIA officers at Guantanamo Bay were using, including mock drowning and withholding food and medicine.