With New York Times reporter Judith Miller's release from jail Thursday and testimony Friday before a federal grand jury, the role of I. Lewis "Scooter" Libby, Vice President Cheney's chief of staff, came into clearer focus. Libby, a central figure in the probe since its earliest days and the vice president's main counselor, discussed Plame with at least two reporters but testified that he never mentioned her name or her covert status at the CIA, according to lawyers in the case.

His story is similar to that of Karl Rove, President Bush's top political adviser. Rove, who was not an initial focus of the investigation, testified that he, too, talked with two reporters about Plame but never supplied her name or CIA role.