If confirmed, Robert Mueller, 56, will inherit a proud, insular agency that is facing three investigations and has been embarrassed by a string of recent controversies, from the mishandling of documents in the Oklahoma City bombing case that prompted a delay in Timothy McVeigh's execution to the arrest of accused spy Robert Hanssen, a top-ranking FBI counterintelligence operative. The problems have prompted loud calls on Capitol Hill for a change in the FBI's culture.
During Mueller's long career as a prosecutor he earned a reputation for toughness and has won the support of leaders of both parties. Most important, he is known as a skilled manager who is not afraid to make changes, a quality that appealed to the White House given the near-universal calls for changes in the FBI.
In a brief Rose Garden ceremony, Bush seemed to acknowledge the questions that arose after Mueller emerged as the front-runner several weeks ago but was not immediately named FBI director, leading to speculation that Bush chose him only reluctantly.
"He was chosen with great care and has my full confidence," Bush said. "The FBI has a great tradition that Mr. Mueller must now affirm and some important challenges he must confront. Like the Department of Justice, the FBI must remain independent of politics and uncompromising in its mission."
Mueller praised the bureau as "the foremost law enforcement agency in the world" and said, "I look forward to working with the thousands of dedicated men and women who are agents and employees of the FBI, to enforce our nation's laws fairly and with respect to the rights of all Americans."
He becomes the federal agency's sixth director, taking over from Louis Freeh, who came to the job eight years ago amid high expectations but left with a mixed record.
Since legendary FBI chief J. Edgar Hoover retired in 1972, the FBI director has served a term of 10 years, a long period intended to guarantee his independence from the president.
That means Mueller could be in office two years after Bush leaves even if the president is re-elected. Mueller's success or failure could be one of Bush's longest-lasting legacies.
The FBI has expanded dramatically in recent years, adding thousands of agents and dozens of offices overseas. It is contending with new threats as varied as cyber-crime, biological terrorism and organized crime that operates across borders at will.
Joseph diGenova, the former top federal prosecutor in Washington, D.C., said one of Mueller's main qualifications is his ability to make difficult changes.
"He is a tough-minded former Marine who knows how to fire people," diGenova said. "His experience at the highest levels of the Justice Department and as a U.S. attorney will make him both sensitive and certain about what needs to be done inside the bureau to restore public confidence in it."
Some suggested that Mueller's lack of experience within the FBI could hurt him. Freeh, in contrast, had served as an FBI agent before becoming a federal prosecutor and judge. But others argue that change can best be implemented by an outsider. "There is a delicate balance they were trying to strike between someone who could restore confidence as an outsider, which Mueller is, and someone who knows enough about the FBI so that he could start off running when he takes over," said Ronald Kessler, author of "The FBI: Inside the World's Most Powerful Law Enforcement Agency."
Mueller appears unlikely to face trouble in his Senate confirmation, though lawmakers' displeasure with the FBI ensures that the hearings will be lively. Sen. Charles Grassley, R-Iowa, the bureau's chief Senate critic, said he is reserving judgment until he meets Mueller.
"Depending on my private conversations with him, as well as what is brought out in the committee, I will decide my support or non-support for him," Grassley said. "This could be a once-in-10-years opportunity to make the changes in the FBI that need to be made."
Sen. Patrick Leahy, D-Vt., chairman of the Senate Judiciary Committee, was equally noncommittal. "I will be interested in hearing Mr. Mueller's views, his willingness to acknowledge and correct the bureau's problems and his ability to meet these challenges head-on," Leahy said.
Mueller is a conservative Republican, but one with unusual bipartisan credentials. He was appointed to his current prosecutor's post in San Francisco by President Bill Clinton with the strong support of Sen. Barbara Boxer, D-Calif.
He headed the Justice Department's criminal division under Bush's father, and he temporarily served as Attorney General John Ashcroft's deputy in the first few weeks of the current administration.
Bush, who named his Cabinet with unusual speed, has found the search for an FBI director anything but smooth. Though the post once was one of the most desirable jobs in Washington, it has become much harder to fill because of the political battering the bureau has taken recently.
Freeh announced his resignation two months ago and has been gone for two weeks. Bush interviewed Mueller in the Oval Office several weeks ago but appeared reluctant to make his nomination final, leaving Mueller hanging awkwardly as the White House cast about for other candidates.
Some on Bush's team feared Mueller lacked the clout and credentials to make needed changes in the agency, according to some familiar with the process. But White House spokesman Ari Fleischer insisted Bush simply wanted to take care in making the choice.
"The FBI is in a position unlike almost any other position," Fleischer said. "It's a fixed 10-year term. It has a jurisdiction and an impact on people's lives that is very direct and very pronounced. And it's the type of decision that a president should weigh carefully and thoroughly before naming someone, and that's the approach the president has taken."
Mueller will need to show skill in at least three different tasks: handling external criticism with political deftness, persuading a suspicious rank-and-file to accept changes, and making law enforcement decisions with enough dexterity to avoid future blow-ups.
When Freeh took office eight years ago, many thought the former FBI agent, prosecutor and judge appeared to be was a perfect fit for the job. But his tenure was rocky.
The FBI was still reeling from the 1992 Ruby Ridge incident in which a sniper shot and killed the wife of separatist Randy Weaver, and the 1993 raid on the Branch Davidian compound at Waco, Texas, in which 80 people died. The storied FBI laboratory saw its reputation suffer as employees testified that results were altered in a number of cases, and the bureau botched the investigation of a 1996 bombing at the Atlanta Olympics, wrongly fingering security guard Richard Jewell.
At the same time, the FBI became entangled in a political mess when Freeh found himself publicly at odds with Clinton and former Attorney General Janet Reno over a potentially explosive investigation of campaign finance violations.
The subsequent Hanssen and McVeigh episodes cast a cloud over Freeh's departure.
In the end, critics say Freeh lacked the administrative skills to implement far-reaching change. The question many are asking is whether Mueller has those skills.
"I want a person who will change a culture that is inclined towards headlines and public relations, rather than a nuts-and-bolts approach that seeks the truth," Grassley said. "There is a culture that, particularly in high-profile cases, seems to believe that the FBI can do no wrong."
Chicago Tribune staff reporter Bob Kemper contributed to this article.