Maybe they were desperate for a lead that could help solve the Centennial Park mystery. Or perhaps they wanted to educate the public about the tell-tale signs of bombmaking.
Either way, investigators' unusual plea for help this week takes citizen involvement in crime-solving to a new level.
In revealing hundreds of details about the July 1996 Olympic bombing and two other attacks that rattled Atlanta over the next seven months, federal investigators are involving the public in the minutiae of cases as seldom has been done before.
"I don't know that we've ever displayed a bomb's components to the degree we have here," says Laurence Murray, who heads the investigation for the US Bureau of Alcohol, Tobacco and Firearms (ATF).
At the news conference, investigators laid out bombmaking ingredients as neatly as a chef displays food items on a cooking show. An FBI inspector pointed out the common and the quirky - from piles of nails and rolls of utility tape to strangely twisted wire and jerry-rigged backpacks.
Investigators say they "strongly believe" someone in the public has come into contact with the bomber or bombers because the items are so commonplace. Authorities believe all three Atlanta bombings were committed by the same person or group.
To some, the government's approach is a long shot. "I think partly they're grasping," says Noah Chandler of the Center for Democratic Renewal, an Atlanta-based group that tracks domestic terrorism. "But at the same time, this is how they may catch a bomber - by these very small details. The only way they're really going to able to catch anyone now is by some minor flaw."
Building on success
In making the rare appeal, investigators are also building on the successes of public involvement in other high-profile cases, such as the Unabomber case now being tried in California and the tracking of serial killer Andrew Cunanan.
But federal agents may have another motive in releasing details about bomb components: raising public awareness to prevent or quickly solve attacks they have reason to believe may come in the future.
"The FBI may be expecting something to happen soon. This is a way to get [public] awareness back up," Mr. Chandler says. "The implicit message may be, 'Let's watch out in those areas that have been targeted.' "
Authorities deny having any information about future attacks. But the AFT's Mr. Murray does say, "public safety is a big concern," and is one reason investigators have been so forthcoming.
Awareness-raising by federal authorities in this way is groundbreaking as well. In the United States, efforts to inform the public about terrorism have lagged far behind those of European countries. In places like Paris and London, people are regularly reminded by signs and announcements to watch for abandoned cars or packages. In the US, few cities have even drafted plans for how their emergency workers should respond to bombings.
To be sure, bombing attacks have soared in the US in recent years - a time when bombmaking instructions became as accessible as the computer or the library, and materials are easily obtained by walking into a hardware store. ATF statistics show that criminal explosions and attempted explosions almost tripled in one decade - from 1,103 in 1985 to 3,163 in 1994. The number of pipe-bomb attacks has doubled in the past 10 years.
If a tip does help in the probes, or if releasing information about bombs plays a role in preventing future attacks, the strategy of going public - and the divulging of considerable detail - will likely be used in other cases, authorities say.
Letting the public in as much as possible is "a pretext for communicating, a way to persuade, perhaps," says Neil Livingstone, a security consultant in Washington. "It's a way of saying, 'Hey, if someone's out there, we're still interested in what you have to tell us.' "