The man looked Middle Eastern, the callers said, and he was skulking around the American Legion Bridge on the Capital Beltway. Heavy traffic whizzed past, crossing the Potomac on a night when tensions were already high because of a big event on the Washington Mall.
Maryland State Police arrived to question the man, and his story didn't add up. When three friends came to retrieve him, their stories seemed just as curious. The mystery deepened when one of their names turned up on a watch list for terrorism.
Such was the scene Sept. 4, after several passing motorists heeded the call of one of those big messages posted at times on up to 54 signs along the state's major highways, from the Bay Bridge to Western Maryland: "Report suspicious activity. Call 800-492-TIPS."
Although the episode proved to be a false alarm - the name was a match, but not the man, and an emergency inspection of the bridge came up clean - the case was an early test of both the tip line and Maryland's nascent terror-response machinery.
People are now phoning in their suspicions to the 800 number at a rate of about 30 per day, and since Nov. 3 the calls have been routed to a two-story office in Calverton, where about 40 local, state and federal officials are running the new nerve center for Maryland's relatively quiet front in the war on terror.
Business so far has been pretty slow at the center in Prince George's County, and the phone tips seem to be covering a wide range of concerns. Some report sightings of people shooting videos at power plants or airports, while others merely report abandoned vehicles. A few callers have informed on neighbors, or on strangers engaging in "un-American activity," indicative of skittish times in which fears are easily stirred, and people seem to be groping to define what the state means by "suspicious."
Only a few tips, such as the bridge incident, have been deemed serious enough to merit immediate attention, and none has resulted in an arrest on terrorism charges, though "there are some things that are being investigated and followed up on," said Lt. Col. Steve Moyer, head of homeland security and intelligence for the state police.
"We're the first [anti-terror] center in the country to have federal, state and local officials all working together under one unique command structure," said John Spiroff, a Baltimore County police captain and director of the Calverton center (formally the Maryland Coordination and Analysis Center). "We're the model, and I use that term proudly. Everyone at the center has top-secret clearance."
The quick and easy sharing of information between law enforcement agencies, not a strength before the Sept. 11 attacks, has been one of the first benefits to arise from the operation, Moyer said.
"It's the best I've ever seen, and I've been in the business 21 years," he said. "A lot of turf issues have gone off to the side."
But the toll-free tip line is the most public part of the effort. Round-the-clock staffing for Calverton's "watch section" had fielded 2,122 calls through Friday. Of those, 261 came from law enforcement personnel around the state and the rest came from the public. Spiroff described 279 as "terrorism tips or leads" and 122 as tips on other crime, such as drug dealing.
For security reasons, officials tend to be vague when describing specific calls, and that can make it sound as if some callers are being overzealous. Moyer mentioned tipsters who "call up and say that there are these groups meeting, and they're not in support of the war."
Does that mean people are reporting anti-war activists as "suspicious"?
"There's been more to it than that," he said, declining to elaborate because of confidentiality concerns. "Under the Patriot Act there are some people we monitor. ... Some are here on visas."
The nature of such calls and explanations makes civil libertarians uneasy.
"I don't think anyone could very reasonably say that the police shouldn't solicit tips," said David Rocah, staff attorney for the American Civil Liberties Union of Maryland. "There is nothing inherently wrong with that. I think the critical issue is how the police react to the tips they get and what they do with the information."
The case of the man on the Beltway bridge, back when tip calls were being fielded at an office in Columbia, demonstrates the efficiency - and perhaps the potential for overzealousness - under the new setup.
Law enforcement officials were already on alert that night because of large crowds gathered on the Mall for the NFL Kickoff event. So, when callers said they'd spotted a man wandering not only on the bridge, but heading below it, state police rushed to the scene.
They took the man to the barracks in Rockville. He told them his friends had dropped him off because he was feeling ill. When the friends returned to the bridge to pick him, police took them into custody. They said they'd dropped off the man because of an argument. Then one of their names popped up on a watch list.
"We determined we needed to get a state highway crew out there to investigate and inspect the bridge that night," Moyer said.
The inspection showed no problems, and the watch list match turned out to be a case of mistaken identity. Under the pre-9/11 ways of doing business, Moyer said, "We would have sent the information over to the local FBI office, and we may not have ever heard anything back. Or a whole week might have gone by."
But before Sept. 11, the man on the bridge might not have aroused suspicion, and there would have been no toll-free number posted on the highway soliciting calls.
The rest of the operation at Calverton, which focuses on analyzing the information that comes in, is still building up to full strength, said Dennis R. Schrader, who since July has headed Gov. Robert L. Ehrlich Jr.'s new Office of Homeland Security.
"We're saying to the local jurisdictions, 'We'd like you to participate in this so your people will have access to the center,'" Schrader said.
The center's most recent flurry of activity came Friday, when the U.S. Department of Homeland Security downgraded the nation's terror alert level from orange to yellow.
"They organized a conference call and briefed all the local officials around the state," Schrader said. "This allows us to push out information very quickly. It really is a magnificent effort, with a lot of people working collaboratively."