Whether or not special counsel Patrick J. Fitzgerald wins a conviction against former vice presidential adviser I. Lewis "Scooter" Libby, legal analysts say he already may have proved what many once doubted: that the Justice Department can deal credibly with allegations of White House wrongdoing.

The CIA leak case in the Bush White House is the first high-level scandal since 1999, when the federal law that had authorized past independent counsel investigations had been allowed to lapse because of frustration by both Republicans and Democrats with past inquiries' cost, length and lack of accountability.

But, the analysts say, Fitzgerald's investigation has maintained its focus, there have been no leaks from his grand jury and he has shown restraint by indicting just one person so far -- declining even to name publicly other people he might have targeted. The main reason his 22-month investigation has gone on so long is that he spent months in a related court fight over the right to question reporters about their confidential sources.

Fitzgerald's appointment "eliminated the risks of the old independent counsel statute, and it's worked just beautifully," said John Barrett, a professor of law at St. John's University who served as a senior aide to Iran-contra independent counsel Lawrence E. Walsh for five years. "It looks like a traditional, responsible, very aggressive but professional prosecutor's work."

The 1978 independent counsel law was enacted as a response to the 1973 "Saturday Night Massacre," in which President Richard Nixon ordered the firing of Archibald Cox, a Watergate special prosecutor who had been appointed by his own attorney general. That experience created a lasting concern about conflicts of interest within the executive branch.

Under the law, which was renewed every five years in slightly different versions, the independent counsel was appointed by a three-judge panel that was itself selected by the chief justice of the United States. The law survived a Supreme Court challenge from opponents who saw it as creating an unaccountable, fourth branch of government.

But after the Republican administration of President Ronald Reagan was bruised by Walsh's nearly seven-year investigation, and the administration of Democrat Bill Clinton was battered by Kenneth Starr's probe, Congress let the law expire in 1999.

Fitzgerald, the U.S. attorney in Chicago, was appointed in December 2003, after the Bush administration yielded to criticism of its initial plan to let Attorney General John D. Ashcroft supervise a probe.

Ashcroft recused himself, giving his then-deputy, former career prosecutor James B. Comey, authority over the case. Comey chose Fitzgerald, whom he already knew and respected.

In what would prove a crucial step enhancing Fitzgerald's independence, Comey waived 1999 special counsel regulations that would have required Fitzgerald to notify the attorney general in advance of major prosecutorial decisions and to submit a confidential report at the conclusion of his investigation.

As a result, Fitzgerald had almost as much autonomy as an independent counsel would have -- though, unlike an independent counsel, he was still technically subject to being fired by the Bush administration if he clearly abused his authority.

The absence of any reporting requirement meant that Fitzgerald had to adhere to the traditional prosecutorial rule against publishing any information outside of an indictment. In contrast, independent counsels were required to submit exhaustive findings to the three-judge panel -- and Starr made a now-famous impeachment report on Clinton to Congress.

Legal analysts said the Fitzgerald arrangement shows that, whatever temptations the Bush Justice Department might have had to tilt the investigation in its favor, those were effectively counterbalanced because the administration itself would have been politically accountable if it mounted a transparently self-serving investigation.

And whereas past administrations could -- and did -- bemoan the alleged abuses of independent counsels who had been appointed by judges, the Bush administration is in a far weaker position to complain about the results of an inquiry it organized itself.

"As a result of the way he was appointed, the attacks coming from the White House will have to be more muted," said Katy Harriger, a professor of political science at Wake Forest University who has written a book about the history of the independent counsel.

Fitzgerald's probe also has cost far less than some past independent counsel investigations. According to recent reports by the congressional Government Accountability Office, Fitzgerald spent just over $724,000 in the first 15 months of his investigation.

This was less than half the $2.1 million David M. Barrett, an independent counsel appointed in 1995 to investigate then-Housing secretary Henry G. Cisneros -- and still operating 10 years later -- spent between September 2003 and September 2004.

Some worry that Fitzgerald, who said his investigation is not over, has too much latitude because of Comey's decision to waive the 1999 regulations.

Neal Katyal, a Georgetown University law professor who as a Clinton administration official helped draft the regulations, said it was politically courageous of Comey to give Fitzgerald such wide authority but also "structurally dangerous," and that it would have been preferable to name an outside lawyer, as the regulations suggested.

"In terms of raw power, he's the same as any independent counsel," Katyal said of Fitzgerald. He added that Fitzgerald had shown good character and had not yet abused his power, but "this should not turn on individual character."

Special Counsel Patrick J. Fitzgerald, at lectern, with FBI Special Agent Jack Eckenrode, announces the grand jury's decision.