For the past century the FBI has made its name rounding up bad guys: bank robbers, kidnappers, spies and mobsters … for bringing to justice those whom FBI director Robert Mueller says committed "some of the most unspeakable crimes that have taken place in the last century."
But Mueller acknowledges that the Bureau today is at a turning point.
In the wake of September 11, 2001, the Bureau has made terrorism its top priority. It's no longer mostly about tracking down criminals after they've committed crimes; it's about stopping terrorist acts before they happen.
"It may be a little more difficult, and difficult in different ways than what we have been successfully doing in investigating crimes over the last 100 years," Mueller said, "but it is our mission and we will be successful at it."
But Americans are watching to see if the FBI is really up to the new challenge.
It's a far cry from the old shoot-'em-up days of the past.
It all started with a small investigative wing in the Justice Department, during Theodore Roosevelt's presidency. But it wasn't until J. Edgar Hoover was brought in that the modern-day Bureau took shape:
When Hoover took over in 1924, the Bureau was mired in that political scandal of the day, Teapot Dome. The Secretary of the Interior was going to jail for taking bribes; the attorney general had been asked to resign.
FBI historian John Fox says that Hoover quickly moved to strengthen the Bureau … and burnished his own image…
"The FBI emerged in the 1930s as a nationally-known organization because of its fight against gangsters like John Dillinger, "Baby Face" Nelson and "Pretty Boy" Floyd, you know, all those guys with the cool nicknames."
It was a gangster, "Machine Gun" Kelly, who gave FBI agents their cool nickname. As Walter Cronkite described in a 1957 CBS broadcast, "When FBI agents closed in on him, he wimpered, 'Don't shoot, G-men!' Kelly was soon forgotten, but the name 'G-Men' stuck."
Over the years, J. Edgar Hoover became preoccupied with something other than gangsters:
"Communists," he said, "have been, still are, and always will be a menace to freedom, the democratic ideals, and the worship of God and to America's way of life."
FBI critics charged that it was Hoover's obsession with communists and those he called "moral degenerates" that led to the FBI's domestic spying program. The Bureau kept files on and harassed high-profile Americans, like Dr. Martin Luther King Jr.
"I think that is something we regret," Fox said. "It is something that really shows where we should not be going."
In fact, the FBI has long struggled to balance conducting investigations with protecting civil liberties. It is something that resounds today in the fight against terrorism.
Braver asked Mueller if he is worried that investigators will round up the wrong people in order to get the right people?
And intrinsic to that success is the quality of FBI agents. Some of their training at the Bureau's academy in Quantico, Virginia has changed little over the years.
But there are more women now - about 20% - and more minorities - again, 20%.
Agents are schooled in following the letter of the law in interrogations. There is new focus on counter-terrorism training, too.
But to some, whether the FBI should be the front line against domestic terrorism is an open question:
Eric Lichtblau, a Pulitizer prize winning reporter for The New York Times and author of a recent book on the Bush adminstration and the law, says that while the Bureau has made some progress, it is still (by the assessment of outside experts) far behind where it needs to be.
Lichtblau says one cannot simply apply the skills used to disrupt organized crime or drug traffickers to catching terrorist.
"I think it requires more in the way of analytical skills," he said. "It requires cultural understanding of Middle Eastern ways, it requires linguistic and language skills … a lot of skills that the FBI doesn't have, even now, seven years [after 9/11]."
Mueller disputes accusations that the FBI was slow to pick up on terrorism as a threat to this country.
"If you look at the success of the FBI in New York bringing to justice those involved in the 1993 bombing of the World Trade Center, the work that was done to investigate the East African bombings, I think it was 1998, the Cole bombing …the Bureau has done substantial work in addressing terrorism."
In the early '90s, the FBI did run an undercover operation that disrupted a plot to bomb bridges and buildings in New York. But when it came to September 2001, Lichtblau said, "There were a handful of situations where the FBI certainly had information in its own files that could conceivably have altered the events of 9/11. And the lack of coordination and communication between the FBI and CIA led to the failure to identify them."
And while the Bureau helped pioneer fingerprinting, DNA analysis, and more sophisticated forensic evidence techniques, it has lagged far behind in computer technology.
"There are stories about how on 9/11, the FBI was literally unable to send files from its foreign offices to Washington with images of the hijackers," Lichtblau said.
Mueller accepts as "fair criticism" charges that the FBI had a lot of information but wasn't able to connect the dots. "So we had to put into place those capabilities," he said.
The FBI is still struggling to update its computer system, and to improve communication with the CIA and other agencies.
But some suggest the Bureau should just stick to combating traditional crime:
"The FBI's whole mission is in question," Lichtblau said, "and there's serious doubt, even now, whether or not they're up to the task of remaking themselves to prevent the next terrorism attack."
But Mueller insists that the FBI is proving its worth every day:
"I think we have done a very good job since September 11 of assuring the American people, particularly from terrorist attacks, both domestic and international, and every time I say that I knock on wood, 'cause I know we can expend our efforts. But to a certain extent, there is happenstance in there."
Braver asked the director, "What keeps you up at night?"
"It is weapons of mass destruction in the hands of some terrorist, if not today then tomorrow, a few weeks or months down the road."
Mueller says the Bureau's agents and analysts are working intensely to stop such an attack before it happens. In addition, they're keeping focus on all their other law enforcement tasks, including locking up mobsters and tracking down spies who sell state secrets.
Mueller says that after 100 years the FBI has to be able to do it all.
"It's neverending," he said. "I mean, the threats of today are not the threats you are gonna see five or ten years down the road. What you want to do is put the FBI in a posture where it is able to identify those threats as early as possible, and move resources to address them immediately."