Careful, Congress

Atty. Gen. Michael B. Mukasey has displayed a commendable sensitivity to appearances in asking a respected prosecutor from outside the Beltway to investigate whether laws were broken in the destruction of videotapes of "enhanced" CIA interrogations. Members of Congress who are welcoming the appointment of John H. Durham, an assistant U.S. attorney from Connecticut, shouldn't complicate his assignment by forcing key figures in the criminal investigation to testify on Capitol Hill -- at least not now.

Like Patrick J. Fitzgerald, the U.S. attorney in Chicago who led the prosecution of former vice presidential aide I. Lewis "Scooter" Libby, Durham is a career prosecutor with a reputation for integrity and persistence. Unlike Fitzgerald, Durham will not operate outside the usual Justice Department chain of command -- a difference that has prompted a complaint from Rep. John Conyers Jr. (D-Mich.), the chairman of the House Judiciary Committee.

But Durham, who will report to the deputy attorney general, is in fact if not in name a special prosecutor, and free of the baggage that would have burdened Chuck Rosenberg, the U.S. attorney in Alexandria, Va., who otherwise would lead the investigation. Rosenberg, who has recused himself from the tapes case, acknowledged last year that the Justice Department belatedly learned that the CIA had taped the interrogations of three potential witnesses in the terrorism case against 9/11 conspirator Zacarias Moussaoui.

Whether laws were broken isn't the only question about the destruction of the tapes in late 2005. Congress has a legitimate oversight interest in determining how and on what supposed legal authority the destruction took place and who chose not to make the tapes available to the 9/11 commission. A full understanding of the circumstances surrounding the destruction of what might have been evidence of torture also could aid Congress in legislating more accountability.

So Sen. John D. Rockefeller IV (D-W.Va.), the chairman of the Senate Intelligence Committee, was right to insist that, despite Durham's investigation, Congress will press forward with hearings. But history suggests that if Congress wants Durham to succeed, it may have to scale back its own investigation.