"This is a very serious matter, and compromising national security information is a very serious matter," Fitzgerald said. "But the need to get to the bottom of what happened and whether national security was compromised by inadvertence, by recklessness, by maliciousness is extremely important. We need to know the truth. And anyone who would go into a grand jury and lie, obstruct and impede the investigation has committed a serious crime."
As for Rove, his lawyer, Robert D. Luskin, said in a statement that Fitzgerald said "he has made no decision about whether or not to bring charges, and that Mr. Rove's status has not changed."
But a source close to Rove said that new information brought to Fitzgerald's attention this week appeared to have brightened the legal picture for Rove and could spare him an indictment. But the source added that Rove is "not out of the woods yet."
Fitzgerald's comments also seemed to suggest that he would not seek further indictments, saying, "the substantial bulk of the work in this investigation is concluded."
He dampened speculation about more big breaks in the probe, saying, "We're not quite done, but I don't want to add to a feverish pitch."
The grand jury that handed down the indictments expired yesterday, but Fitzgerald said he would empanel another one, as is routine,"to consider other matters."
Democrats pounced on the news on Libby as evidence of deeper corruption by Bush's administration, and proof of the lengths to which the White House was prepared to go to defend its policies.
"Today is an ominous day for the country, signifying a new low since Watergate in terms of openness and honesty in our government," said Sen. Edward M. Kennedy, a Massachusetts Democrat, who called the charges "an indictment of the vicious and devious tactics used by the administration to justify a war we never should have fought."
Sen. Barbara A. Mikulski, a Maryland Democrat who sits on the Intelligence Committee, called the charges "grave, disturbing and shocking," adding that the alleged crimes appeared to be "part of a larger strategy by senior White House staff to manipulate the information that falsely led America into war."
Republicans, many of them relieved that Rove had escaped charges, were mostly mum on the investigation yesterday, but some said they were cheered that no one at the White House had been accused of breaching national security with a leak.
"If there was no underlying crime committed, then one has to ask, why then would you bring five counts against a servant in the government who may or may not have done something wrong?" Sen. Orrin G. Hatch, a Utah Republican, told CNN.
Still, Rep. Christopher Shays, a Connecticut Republican, said Bush should address the situation head-on, condemn those involved, and move on.
"No one is indispensable," Shays said. "The president needs to send a clear message as to what he expects from his people. And if he does that, it's all going to be fine."
Andrew H. Card Jr., the White House chief of staff, who received Libby's resignation letter, moved quickly to calm Bush's team, on pins and needles in recent weeks as they awaited high-level indictments.
"We have always placed the people's business ahead of all else," Card wrote in a memo to the White House staff. "This is our duty as public servants, and the American people deserve no less."
The Justice Department opened the investigation in September 2003 into how Plame's identity surfaced, after Novak's July 14, 2003, column named her as an "operative on weapons of mass destruction."
Fitzgerald began his investigation in December, after then-Attorney General John Ashcroft recused himself.
Novak's column ran the week after Wilson wrote a New York Times op-ed article accusing Bush of manipulating intelligence. Plame suggested her husband for the Niger mission, Novak wrote in his column, attributing the information to administration officials.
Another White House aide, described in the indictment as "Official A," told Libby he had spoken with Novak about Plame and her involvement with Wilson's trip, and that Novak would be writing about her. "Official A" is Rove, said a source close to him.
During the course of Fitzgerald's probe, at least two journalists, Time's Matt Cooper and The New York Times' Judith Miller, testified that they discussed Plame and her CIA employment with Libby.
Libby is accused of giving gave false accounts to investigators and the grand jury about those conversations and one he had with NBC's Tim Russert, the indictment said.
In his conversation with Cooper, Libby told the inquiry, he mentioned that other reporters were saying Wilson's wife worked for the CIA, but he didn't know if it was true. In fact, the indictment said, Libby flatly confirmed to Cooper that he had heard Wilson's wife worked for the agency.
Wilson, who has accused the administration of outing his wife to retaliate against him for undermining its case for the war, proclaimed yesterday "a sad day for America."