Karl Rove (search) is getting a fourth and likely final chance to convince grand jurors he did nothing criminal in the CIA leak case, an appearance that carries some risks as prosecutors are close to wrapping up their probe.

Rove, who long has been one of President Bush's closest aides, could appear as early as Friday, and prosecutors are warning him there is no guarantee he will not be indicted.

The White House has shifted from categorical denials two years ago that Rove or Vice President Dick Cheney's chief of staff, I. Lewis "Scooter" Libby (search), were involved in the leak of a covert CIA officer's name to "no comment" today.

Special Counsel Patrick Fitzgerald's criminal investigation could produce indictments and has caused major political problems for the Bush administration. The grand jury's term is due to expire Oct. 28.

The spotlight recently has fallen on Libby, who was the focus of prosecutors' questions in two grand jury appearances by New York Times reporter Judith Miller (search). She detailed her conversations with the vice president's top aide about the covert CIA officer, Valerie Plame (search), and her husband, Bush administration critic Joseph Wilson.

Fitzgerald has a variety of options as he weighs whether anyone broke a law that bars the intentional unmasking of a covert CIA officer. Defense lawyers increasingly are concerned Fitzgerald might pursue other charges such as false statements, obstruction of justice or mishandling classified information.

For the White House in 2004, the good news about Fitzgerald's probe was that it didn't become an issue during the presidential election year. Witnesses underwent questioning, including Bush and Cheney, White House records were turned over to the grand jury and the administration pledged full cooperation. The president promised to fire any leakers.

Rove, a Texas political consultant who rose through the ranks of Republican politics with the late GOP adviser Lee Atwater, was the architect of Bush's successful drive to re-election. Libby was at Cheney's side during the campaign.

"They are good individuals," White House spokesman Scott McClellan said of Rove and Libby on Oct. 7, 2003. "They are important members of our White House team. And that's why I spoke with them, so that I could come back to you and say that they were not involved. I had no doubt with that in the beginning, but I like to check my information to make sure it's accurate before I report back to you, and that's exactly what I did."

The power to create even more trouble for the administration or wrap up the investigation and return to Chicago, where he is U.S. attorney, lies with Fitzgerald. An experienced prosecutor with a Republican pedigree, Fitzgerald has a reputation for being willing to take on politicians of either political party in corruption probes. Currently, Fitzgerald's office is prosecuting a former Republican governor of Illinois.

The revelations flowing out of Fitzgerald's CIA leak investigation so far offer a public snapshot of Washington at work: A White House with its credibility on the line tries to deal with a political problem by talking confidentially to reporters.

In this instance, the political problem was Wilson and his statements that the administration had twisted prewar intelligence on Iraq. The criticism came as the U.S. military engaged in a fruitless search for weapons of mass destruction in Iraq. The existence of such weapons were the primary reason the administration gave to justify going to war.

Eight days after Wilson made his allegations, columnist Robert Novak identified Wilson's wife as a CIA operative, saying she had suggested her husband for a mission to Africa for the agency.

The trip led subsequently to Wilson's conclusion that the administration had manipulated intelligence to exaggerate the Iraqi threat.

Novak said his sources were two senior administration officials. Rove spoke to Novak about Wilson's wife and is apparently one of Novak's sources. The other is still a public mystery. Novak is believed to have cooperated with Fitzgerald's investigation, though he has declined to comment on the matter.

The White House denials of Rove's and Libby's involvement collapsed three months ago, when Time magazine reporter Matt Cooper testified that Rove had been one of his sources for a story that identified Wilson's wife. Libby was another of Cooper's sources for the story, which asked the question, "Has the Bush administration declared war on a former ambassador?"