Attorney General John Ashcroft (search) is recusing himself as head of the CIA leak probe, the No. 2 man in the Justice Department said Tuesday.

The investigation will be handed over to the U.S. attorney in Chicago, Patrick Fitzgerald, Deputy Attorney General James Comey announced in an afternoon news conference. While Comey will be acting attorney general in the case, he said Fitzgerald will be the special prosecutor in charge of all decision-making related to the investigation.

"He has the power and authority to make whatever prosecutorial judgment he needs" without needing approval from anyone at the Justice Department, Comey said.

Though the investigation will remain within the Justice Department, despite some Democratic calls for an independent probe, Comey said he had no doubts about Fitzgerald's "impeccable judgment."

"For those of you who don't know him, he is a total pro," Comey said. "I chose Mr. Fitzgerald, my friend and former colleague, based on his sterling reputation for integrity and impartiality. He is an absolutely apolitical career prosecutor. He is a man with extensive experience in national security and intelligence matters, extensive experience conducting sensitive investigations and, in particular, experience in conducting investigations of alleged government misconduct."

The investigation was prompted in September after a CIA employee's name was leaked to a conservative columnist during the summer. The employee, Valerie Plame (search), is the wife of former Ambassador Joseph C. Wilson (search). Wilson accused the White House of leaking Plame's name to intimidate him for suggesting that the Bush administration exaggerated intelligence it used in the State of the Union address in January to justify war in Iraq.

The intelligence, taken from a British report, suggested that Iraq had sought yellowcake uranium (search) from the African nation of Niger. Wilson had gone on an eight-day trip to Niger in February 2002 and could not find proof of the claim. The White House has since said that it should not have used the "16 words" referring to the British intelligence on the uranium claim in the State of the Union address.

Comey would not indicate what led Ashcroft to recuse himself, though he said the decision was made and formalized over the last week.

"The attorney general in an abundance of caution believed that his recusal was appropriate based on the totality of the circumstances and the facts and evidence developed at this stage of the investigation," Comey said. "I agree with that judgment."

One official close to the investigation told Fox News that Ashcroft's decision suggests that some sensitive information has been learned in the investigation. The official added that while the recusal does not mean Ashcroft has a conflict of interest, the attorney general "felt he should recuse himself."

The official said that Ashcroft's decision not to recuse himself earlier was a matter of efficiency. "The investigation was moving so quickly that if we had done this earlier, it would have slowed the investigation down," the official said. Fitzgerald could use the same career prosecutors already working on the case if he chooses to, meaning the investigation will not be slowed by the change of authority, he said.

Democratic lawmakers praised Ashcroft's decision.

"The attorney general has made the right decision. Our intelligence agents need to know that we understand the sacrifices they make and that we will come to their defense when someone puts them at risk. An independent investigation is the only way to restore their faith in the government they serve," Sen. Jay Rockefeller, D-W.Va., ranking member of the Senate Intelligence Committee, said in a statement.

"It is not everything we asked for but it come darn close," said Sen. Charles Schumer, D-N.Y., a member of the Senate Judiciary Committee who was the first Democrat to call for an investigation and ask Ashcroft to appoint a special counsel.

But Massachusetts Sen. John Kerry, a presidential candidate and longtime critic of Ashcroft, said President Bush should appoint an independent counsel rather than a special counsel within the Justice Department to investigate the leak.

"As usual, what the Bush Justice Department has done is a half measure and nowhere near good enough to restore public confidence in this tarnished agency," Kerry said. "To put an end to John Ashcroft's failure to obey the law, the president must direct the immediate appointment of a special counsel who is not a political appointee and who is in no way beholden to the fortunes of his administration."

White House Deputy Press Secretary Trent Duffy said the White House was not consulted on the attorney general's decision to recuse himself from the investigation, and was only informed on Tuesday morning as a courtesy. Bush is spending the holidays at his ranch in Crawford, Texas.

"The Justice Department made its decision independently," Duffy said. "Exactly the way it should be."

Duffy added that Bush wants to get to the bottom of the probe, and said in September he welcomes the investigation and has absolute confidence in the Justice Department to do a good job.

Comey said he is confident that the probe is being properly conducted within the Justice Department.

"To date, this investigation has been conducted professionally and expeditiously," he said. "In many ways, the mandate that I am giving to Mr. Fitzgerald is significantly broader than that that would go to an outside special counsel. In short, I have concluded that it is not in the public interest to remove this matter entirely from the Department of Justice, but that certain steps are appropriate to ensure that the matter is handled properly and that the public has confidence in the way in which it is handled."

Comey said that none of the activities that led to Ashcroft's recusal or the appointment of Fitzgerald have delayed the investigation in any way. A dozen agents are working on the case and have not encountered any stalling tactics, two law enforcement officials said Tuesday.

The person who leaked the name could face up to 10 years in prison and $50,000 in fines. Already, the FBI has interviewed more than three dozen Bush administration officials, including political adviser Karl Rove (search) and press secretary Scott McClellan, as well as members of the Defense and State departments and the CIA itself.

No major breaks have occurred yet, and no grand jury subpoenas have been issued, but the two law enforcement officials, speaking on condition of anonymity, told The Associated Press that the focus remains on the White House.

Fox News' Jim Angle and Anna Stolley and The Associated Press contributed to this report.