CHARLIEVILLE, Trinidad and Tobago — Five years ago, as 19 Al Qaeda operatives in the United States put the finishing touches on what would become the Sept. 11 attacks, a frail, asthmatic computer engineer from South Florida paid a visit to this tiny Muslim enclave where he'd lived as a boy.
Adnan Gulshair Muhammad el Shukrijumah, then 25, kept a low profile over the course of the week. He hung out with a small circle of devout older men who were leaders of the local Islamic community. They prayed in mosques, went fishing and enjoyed long walks and leisurely dinners, recalled one of the hosts, Imtiaz Mohammed.
Shukrijumah spoke fondly of his father, an influential Islamic scholar and Charlieville community leader two decades earlier. He also spoke of his family life in Miramar, Fla., his computer technician business and his travels to the Middle East and other exotic locales.
But Shukrijumah said nothing about why he was in Trinidad, nor what his plans were, acquaintances here say.
Two years later, the FBI put out an urgent all-points bulletin for Shukrijumah, depicting him as one of Al Qaeda's most well-trained, intelligent and deadly operatives. He was described as the ultimate "sleeper agent," intent on attacking the U.S., possibly with weapons of mass destruction.
Law enforcement officials and terrorism experts now believe Shukrijumah is one of several young, street-smart leaders of Al Qaeda handpicked by Khalid Shaikh Mohammed, the mastermind of the Sept. 11 attacks, to keep the terrorist network alive and humming in the face of U.S.-led efforts to unravel it.
To be sure, the FBI's record on identifying terrorist plotters since Sept. 11 includes some widely publicized failures. In some cases, law enforcement officials have alleged that suspects were centrally involved in plots, only to back off those assertions when cases moved toward court.
And officials concede that there is much they do not know about Shukrijumah, including what he was doing in Trinidad. Within days of the alert in March 2003, agents arrived on the island looking for him, but he was long gone.
Terrorism authorities both inside and outside the government say they believe Shukrijumah is a major Al Qaeda figure, and the hunt for him is intense, with an FBI team tracking him virtually full time. So far, their quarry has remained elusive.
Whereas Al Qaeda's core followers are young, poor and relatively uneducated, Shukrijumah has attended college and is comfortable with technology. He's also a naturalized U.S. citizen whose appearance would allow him to pass as Latino, Indian or Middle Eastern and who speaks English with no discernible accent, officials say.
That background makes Shukrijumah especially threatening, counter-terrorism authorities say. He is dangerous "because he is so trusted in the organization and because he has traveled in the Western world and is familiar with its customs and procedures," said Joseph Billy Jr., assistant FBI director for counter-terrorism.
Shukrijumah is believed to be "the guy who was reared to replace" Mohammed as an Al Qaeda senior trainer, facilitator and propagandist, playing a central role in the development of hundreds of the network's future soldiers, said Sajjan Gohel, director for international security at the London-based AsiaPacific Foundation. "He is part of Al Qaeda Stage 2." The foundation consults on terrorism assessment for governments.
Shukrijumah has not been charged with a crime, but federal grand juries in Virginia and South Florida are hearing evidence about his activities.
Agents working on the investigation were reluctant to provide many details because of those probes, but the FBI does say that Shukrijumah trained at an Al Qaeda camp in Afghanistan before Sept. 11. There, he learned to handle AK-47s, M-16s, Uzis and other automatic weapons and studied topography, communications, camouflage, clandestine surveillance and explosives, including C-4 plastic charges, dynamite and mines, they say.
The FBI believes Shukrijumah used that training to fight for the Taliban in Afghanistan.
Investigators also believe he was present at a meeting of Al Qaeda leaders in March 2004 near the Pakistan-Afghanistan border, where it appears attendees discussed upcoming terrorist operations in Europe and the United States.
But much of Shukrijumah's life remains a mystery. And the search for him has been through a maze of false leads and vague glimmers.
An Intriguing Lead
The hunt for Adnan Shukrijumah began with a mysterious character called "the South American."
A year after the Sept. 11 attacks, interrogators were desperately trying to determine what other plots might be in the works, and where.