The detective work has begun. Buried in the flight manifest of one of the doomed airliners, investigators have discovered names of people they believe are linked to al-Qaeda, the shadowy network of Islamic terrorists headed by Saudi exile Osama bin Laden.
The clue on the passenger list is just one of hundreds of bits of evidence and tips the FBI is following up in what Attorney General John Ashcroft called perhaps the most massive investigation in American history. But even before the first evidence surfaced, bin Laden topped suspect lists. The coordinated, comprehensive, and ruthless attack bears the trademark of the hunted terrorist, who from remote camps in the mountains of Afghanistan had vowed just three weeks ago to carry out an "unprecedented" attack against American interests.
It was a boast American officials had to take seriously. Bin Laden's operatives had already demonstrated their skill and dedication three years ago when they launched two nearly simultaneous bombings of U.S. embassies in Africa, as well as last year's suicide assault against an American warship, the USS Cole. Still, the incredible feat of hijacking four airliners and striking at two symbols of American power—its money and military might—astonished even veteran counterterrorism experts. "They've probably tested this many times," says Robert Blitzer, former head of domestic terrorism for the FBI. "It was an absolutely brilliant attack."
Yet the attackers left footprints that federal officials are confident will be tracked back to the source. Eavesdroppers at the National Security Agency scrambled in the hours after to monitor phone calls, faxes, or E-mails that might contain messages of congratulations from members of the terrorist groups. Quickly, operators intercepted a phone call between two known associates of bin Laden; they were heard talking about hitting two targets.
The FBI, meanwhile, has 7,000 special agents and support personnel on the case and is reviewing the passenger manifests, rental car receipts, telephone logs, and even videotapes from parking garages and pay phones. Investigators are also searching for the black boxes of the planes, which may contain recordings of the last cockpit conversations. Besides identifying the hijackers, authorities are tracking down accomplices who might still pose a threat to America's air system. Indeed, there is still concern that other terrorist acts are possible. "The U.S. is not fully confident it is done," says a counterterrorism official.
The aggressive investigation is producing leads, and fast: Authorities in Boston identified five Arab men as suspects and seized a rental car; inside they found an Arabic-language flight training manual. In Florida, federal agents searched numerous homes and businesses in connection with the investigation.
Blame game. Though most intelligence sources seem convinced that bin Laden's operatives are behind the attack, the administration has been careful not to accuse him publicly. U.S. officials caution that evidence might show that other groups, perhaps Lebanon's Hezbollah, acted independently to stage the attack. Investigators are also looking hard at Algerian terrorists, who are tied to several millennium terrorist attempts. In 1994, an Algerian cell hijacked an Air France jet and threatened to blow it up over Paris.
It is the precision of this week's operation and its destructiveness that are steering authorities toward bin Laden as the prime culprit. "There is no other group or individual calling for coordinated attacks on the United States," says Larry Johnson, former deputy chief of the State Department's counterterrorism office. For example, bin Laden's followers had the ability to commandeer and fly commercial jets. U.S. News has learned that American intelligence officials had advance knowledge that al-Qaeda was recruiting and training pilots. Attorney General Ashcroft confirms that some of them received pilot training in the United States. Two suspects attended five-month courses at a Florida flight school at a cost of $10,000 apiece, according to its owner, Rudi Dekkers of Huffman Aviation.