Even if White House aides leaked a covert CIA officer's identity, they were simply passing along information they'd already heard from the news media, the administration's supporters maintain in a defense that looks increasing shaky as new evidence accumulates.

Special Counsel Patrick Fitzgerald (search) now knows that Vice President Dick Cheney's chief of staff, I. Lewis "Scooter" Libby, met three times with a New York Times reporter before the leak of Valerie Plame's identity, that Libby initiated a call to NBC newsman Tim Russert and that Libby was a confirming source about the wife of Bush administration critic Joseph Wilson for a Time magazine reporter.

Presidential political adviser Karl Rove (search) has testified that it's possible Libby was his source before Rove talked to two reporters about the CIA operative.

Where Libby first heard the information still isn't publicly known, but a full three weeks before Plame's name first showed up in print, Libby was telling New York Times reporter Judith Miller (search) that he thought Wilson's wife worked for the CIA, according to Miller's testimony.

While Libby maintains that he didn't know Plame's name until it was published in the news media, the now-public evidence suggests Libby at least was aware that Wilson's wife worked at the CIA and that he spread the information.

Prosecutors must determine whether it was part of an effort to undermine the credibility of Plame's husband. Leaking the identity of a covert agent can be a crime, but it must be done knowingly.

Plame's name was first made public by syndicated columnist Robert Novak (search) in July 2003, eight days after Wilson published an op-ed piece in The New York Times saying the Bush administration had manipulated prewar intelligence on Iraqi weapons programs to justify going to war.

Novak's column said Plame worked for the CIA and that she had suggested her agency send Wilson, a former ambassador, on a mission to Africa that raised questions about the prewar intelligence.

Until this week, "the news media did it" was a standard defense among Republicans trying to protect the Bush administration from the political fallout of Fitzgerald's criminal investigation. Loyalists said that even if White House aides had passed on information, they didn't get it from classified sources and were simply repeating what they heard from journalists.

In grand jury testimony shown to Rove, Libby said he had told Rove about information he had gotten about Wilson's wife from Russert, according to a person directly familiar with the information.

Prosecutors, however, have a different account from Russert. The TV network has said Russert told authorities he did not know Wilson's wife's identity until it was published and therefore could not have told Libby about it. Russert also says that it was Libby who initiated the contact with him.

In Miller's case, she was interviewing Libby on June 23, 2003, for a story on the failure to find weapons of mass destruction in Iraq when the vice president's chief of staff suggested a CIA tie for Wilson's wife, Miller has said.

"This was the first time I had been told that Mr. Wilson's wife might work for the CIA," Miller wrote in a first-person account over the weekend.

Miller said this week that she never wrote a story about Wilson's wife because "it wasn't that important to me. I was focused on the main question: Was our WMD intelligence slanted?"