A high-level panel concluded there was no formal policy directing the abuses, which sparked a regional and global outcry.
The head of the panel -- former U.S. Defense Secretary James Schlesinger -- said in releasing the report in Washington yesterday that the prison near Baghdad was in "chaos."
"The abuses that were depicted in the photos did not come from authorized interrogation. They did not come from seeking intelligence. They were freelance activities on the part of the night shift at Abu Ghurayb," Schlesinger said.
But the panel did point to problems at much higher levels. It concluded that senior U.S. officials failed to provide clear guidelines on techniques for interrogating various types of prisoners held at Abu Ghurayb and other places in Iraq. And it said resources should have been shifted to the poorly equipped prison detention unit after problems became apparent.
Another former defense secretary on the panel, Harold Brown, said responsibility for the prison abuses stretches far.
"A degree of responsibility for failure to provide adequate resources to support the custodial and intelligence requirements throughout the theater and also for the confusion about permissible interrogation techniques extends all the way up through the chain of command to include the joint staff of the Joint Chiefs and to include the office of the secretary of defense," Brown said.
Panel member Tillie Fowler, a former member of Congress, described the command structure surrounding Abu Ghurayb as a "labyrinth of confusion."
"It was shocking to find that during the time of the worst abuses that were occurring, it was not clear who, if anyone, was really in charge at Abu Ghurayb. That confusion and lack of leadership exercised by the top commander set a poor example for subordinates to follow," Fowler said.
But the panel members said they would not recommend that Defense Secretary Donald Rumsfeld step down. They commended Rumsfeld's handling of the scandal.
Schlesinger, the panel head, said one immediate effect of the Abu Ghurayb scandal was a slowing in the gathering of intelligence.
"One consequence of the publicity that has been associated with the activities at Abu Ghurayb and the punishments that prospectively will be handed out is that it has had a chilling effect on interrogation operations. It is essential in the war on terror that we have adequate intelligence and that we have effective interrogation," Schlesinger said.
The commission did not make recommendations about disciplinary action against civilian or military officials.
Overall, about 300 allegations of abuse have arisen connected to U.S. detentions in Iraq, Afghanistan, and Guantanamo, Cuba. The report said 66 have so far been substantiated.
The issue of how high responsibility rests for the abuse is part of a number of ongoing criminal cases against some lower-ranking military police soldiers charged with mistreating detainees in Abu Ghurayb.