Christopher Graveline, who prosecuted the case against U.S. soldiers, says there are no simple answers to what caused the abuse, The Detroit Free Press reported Tuesday.
Graveline, 37, has co-authored a book about the scandal along with Michael Clemens, an investigator on the case.
"I hate to think what would have happened if nothing had been done, or if these people had been acquitted," Graveline told the Free Press.
He said the aggressive prosecution of Lynndie England, Charles Graner and other soldiers charged in the abuse case helped partly restore the image of the U.S. military.
Graveline writes in the book the vast majority of the abuse at Abu Ghraib had nothing to do with intelligence collection.
He said the detainees were tormented for sport.