Updated

Whether agents can capture the Al Qaeda (search ) operatives who cased five prominent U.S. financial sites several years ago will show how far U.S. anti-terror efforts have come since the Sept. 11 attacks.

Amid the anxiety and uproar over this week's narrowly targeted terrorist warning to financial institutions, one thing is certain: There were individuals in New York City, Washington and Newark, N.J., three or four years ago watching and taking photos near these buildings for Al Qaeda. They may still be in this country, may even have resumed their surveillance recently.

The U.S. government wants to question them.

"We have needed this kind of foreign intelligence to tell us what are the specific targets so we can work backward," former FBI counterterrorism chief Larry Mefford said of the discovery of detailed surveillance of American targets that was uncovered recently in Pakistan and prompted the warnings.

"You have to have some starting point to locate Al Qaeda operatives that have sneaked into the United States with phony IDs," he said.

Whether the FBI can use this new information "to find and disrupt Al Qaeda networks in this country will tell us whether we have advanced beyond where we were three years ago," said Roger W. Cressey, a White House counterterrorism official in the Clinton and Bush administrations.

Disclosures so far show an intelligence find "with more detail than we had before 9/11," Mefford said. "And I can guarantee you we in the public are just seeing a small splinter of what they have learned."

The material kept secret is being used to find other Al Qaeda operatives. Pakistan has already arrested some. And while there has been a lot of talk this week from federal officials about how well they've worked together, a positive outcome of this manhunt would give credence to those claims.

While federal law enforcement officials frequently boast about cooperation on big cases, the Sept. 11, 2001, tragedy exposed deeply held divisions and long-built walls between competing agencies. Those were nothing new.

Longtime FBI chief J. Edgar Hoover (search) cut off official communication with the CIA; the CIA failed repeatedly to tell the FBI of suspicions about its deadly Soviet mole Aldrich Ames (search ); the Oklahoma City bombing, Sept. 11 and countless other cases led to later reports of how U.S. agencies failed to cooperate in connecting the dots of evidence in advance.

This time the FBI may have gotten identities or partial descriptions of the operatives who did the surveillance and will surely match the captured surveillance photos and documents against old event reports or arrest records related to the five institutions.

Agents will look at any camera footage they can find around these buildings from the last four years. Surveillance cameras "would be well worth checking," former FBI counterterrorism chief Dale Watson said. "Even though it might be a needle-in-a-haystack search."

The FBI found security camera footage showing bomber Timothy McVeigh (search ) at a McDonald's in Oklahoma City the morning of the deadly 1995 bombing; an apartment lobby security camera caught his yellow Ryder truck headed toward the federal building.

The bureau has a taste for labor-intensive investigation. When a scrap of wrapping from a Unabomber mail bomb had colorless indentations that read "Nathan R," the FBI set out to interview every Nathan R in America. It talked to 10,000 before learning that a secretary at the bombing site had jotted that name on a piece of paper she briefly laid on the bomb package sometime before it exploded.

There are at least 33 outdoor, closed-circuit video cameras at street or roof level that overlook streets or parks abutting the World Bank and International Monetary Fund complex in Washington. That figure doesn't include any indoor cameras that view the streets or long-range cameras that can show faces from blocks away clearly enough to read lips.

The 33 cameras are owned by police, the World Bank, the IMF, local parking garages and office building owners. Most commercial entities "record over the same tape every seven days unless an incident caused them to save the tape and put in a new one," said Professor LaTanya Sweeney of Carnegie-Mellon University, who has studied public video cameras.

The District of Columbia police department has video cameras on the World Bank and the IMF. Both roof-level cameras have 360-degree vision and 17-power magnification, and each can view two streets and the park next to the main World Bank and IMF buildings.

This case could produce a major shift in how cameras are used, paralleling the FBI's recent shift from mostly crime-solving to much more attack prevention.

"The cameras now, like the FBI, have been incident-driven. They are set up to be used after an accident or crime to find out what happened," Sweeney said. "It would be very different to monitor them all the time to see if something might happen. And that raises lots of questions for public debate."