The law enforcement officials and others said one of the computer files, which was related to one of the five buildings put on alert, was opened as recently as this January. The CIA and other intelligence agencies are still working to determine whether the file was changed in any way. The file contained photographs of the building in question, a law enforcement official said.
In all, the materials include about 500 photographs, drawings and diagrams, officials said.
A police officer stands guard with an automatic weapon outside the New York Stock Exchange, one of the buildings that al Qaeda has surveilled.
(Richard Drew -- AP)
_____More From The Post_____
Old Data, New Credibility Issues (The Washington Post, Aug 4, 2004)
Security Might Get Tighter Yet, Officials Say (The Washington Post, Aug 4, 2004)
Capitol Police Focused On Terror (The Washington Post, Aug 4, 2004)
Sluggishness Detected in New D.C. Alert System (The Washington Post, Aug 4, 2004)
The ramp-up to Sunday's alert began three days earlier, when acting CIA Director John E. McLaughlin presided over the CIA's daily 5 p.m. counterterrorism meeting. Attended by representatives of every major intelligence agency, such as the FBI, the National Security Agency and the Pentagon, the meeting included extensive discussions of the newly acquired material.
Intelligence officials would later describe it as the most remarkable "treasure trove" of information about an al Qaeda plot that many of them had ever seen. Officials said the documents showed meticulous and long-running surveillance of the targets, including counts of pedestrian traffic, details about employee routines and discussion about the kinds of explosives that might work best to destroy each building.
President Bush was informed Friday morning aboard Air Force One, during his daily intelligence briefing, an aide said. The CIA, which worked around the clock for the next 72 hours translating and attempting to make sense of the material, told Bush about "emerging information that might require us to take preventive action on certain specific targets," the aide said.
Paul Brown, deputy commissioner for public affairs at the New York Police Department, said Commissioner Ray Kelly learned about the emerging information late Friday. Brown said the details were alarming.
"It doesn't take a genius to know that bin Laden would like to hit Wall Street," Brown said, referring to Osama bin Laden, leader of the al Qaeda network. "Now we go to last Friday. We hear very good reconnaissance, and we put it together with what we know and our past experience, and I'd say that our response was rational from our point of view."
The plans for what to release publicly were made during a 90-minute meeting that began at 10 a.m. Sunday in the White House situation room, with some officials calling in over secure phone lines. Bush authorized raising the alert after church services that morning, aides said.
The public alert was preceded by an unusual conference call between Ridge and news executives at 1 p.m. Sunday, in which he talked about "a most unusual set of circumstances where, from a variety of different sources that we continue to exploit, there's a convergence of information that compels us to talk publicly about specific potential targets."
Bush and his top aides said yesterday that they knew much of the information that inspired the terrorist alert was years old but reacted urgently because they saw echoes of the long planning that preceded the Sept. 11 attacks, administration officials said yesterday.
"The fact that the casing began over the course of a longer period of time is consistent with how al Qaeda operates but does not suggest that the information itself was not then outdated or not relevant," White House communications director Dan Bartlett said.
But Ivo H. Daalder, a senior fellow at the Brookings Institution who was a National Security Council official under President Bill Clinton, said it "would have been useful for Mr. Ridge to have explained that information they were acting on was largely old."
"I don't doubt that this information was found -- I don't think they made it up," Daalder said. "But there is a real question of: Are we finding the kind of information that ought to worry and concern us as much as it has at the moment?"
Ridge dismissed such criticism yesterday. "I wish I could give them all top-secret clearances and let them review the information that some of us have the responsibility to review," he said. "We don't do politics in the Department of Homeland Security."
Staff writers Mike Allen, Spencer S. Hsu, Del Quentin Wilber, Dana Priest and Walter Pincus in Washington and Michael Powell in New York contributed to this report.