A senior Justice Department official said that Holder envisioned an inquiry that would be narrow in scope, focusing on “whether people went beyond the techniques that were authorized” in Bush administration memos that liberally interpreted anti-torture laws.

Current and former CIA and Justice Department officials who have firsthand knowledge of the interrogation files contend that criminal convictions will be difficult to obtain because the quality of evidence is poor and the legal underpinnings have never been tested…

“I don’t blame them for wanting to look into it,” said a former high-ranking Justice Department official familiar with the details of the program. “But if they appoint a special prosecutor, it would ultimately be unsuccessful, and it would go on forever and cause enormous collateral damage on the way to getting that unsuccessful result.”…

An inquiry also would probably drive a new wedge between the CIA and the Justice Department, agencies with a fractious history that have struggled to work more closely together since the Sept. 11 attacks.