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.
While questioning an Al Qaeda detainee in Pakistan, they got an intriguing lead. An operative known only as the South American had been discussing with Al Qaeda leaders new ways of attacking U.S. citizens, including blowing up apartment buildings with natural gas and spraying people with cyanide in nightclubs, the prisoner said.
Authorities knew little about this person except that he was well trained by Al Qaeda, connected to its top leadership and on the loose, perhaps plotting an attack on U.S. soil.
And their anxiety was growing. By early 2003, detainees held overseas and at the U.S. prison at Guantanamo Bay, Cuba, were telling interrogators that Al Qaeda leaders had sent new terrorist operatives into the United States to launch follow-up attacks.
Unlike the Sept. 11 hijackers, the detainees said, these new teams included second-generation immigrant Muslims who had lived in the U.S., understood its customs and could operate under the radar of law enforcement.
When asked which operative was most likely to launch a U.S.-based attack, many captives mentioned one particular figure with an almost mythical reputation as a ruthless militant. His nom de guerre was Jaffar al Tayyar, a reference to an Islamic hero who had fought beside the prophet Muhammad.
But his identity, too, was a mystery.
The pieces began to come together in early March when Mohammed was captured in Pakistan and his computers, phones and other electronic gear were seized.
The evidence confirmed that Mohammed had been sending "Westernized" Al Qaeda soldiers on missions into the U.S. and other countries.
And when Mohammed was shown a photograph of Shukrijumah, he identified him as Tayyar, U.S. counter-terrorism officials said.
By then, U.S. authorities were concluding that Shukrijumah was also the shadowy South American, an apparent reference to his time spent in Trinidad and nearby Guyana.
To their dismay, they realized that one of Al Qaeda's best-trained operatives had been lurking -- and perhaps plotting -- in the United States since long before the Sept. 11 attacks.
Father a Missionary
Many Al Qaeda devotees came to the cause of militant Islam as young men; Shukrijumah grew up in it.
His father, Sheik Gulshair el Shukrijumah, was a Muslim missionary from Guyana who worked for the government of Saudi Arabia.
In the early 1990s, Sheik Gulshair was assigned to the Al Farouq Mosque in Brooklyn, some of whose congregants were soon linked to two Islamist terrorist plots: the first World Trade Center bombing in 1993 and an unsuccessful conspiracy to blow up the United Nations, Holland Tunnel and other landmarks.
Sheik Gulshair came to the FBI's attention because of translation work he did for a blind cleric named Omar Abdel Rahman, who was implicated in the first World Trade Center bombing. Abdel Rahman, head of an Egyptian terrorist organization linked to Al Qaeda, was sentenced to life in prison for his lead role in the plot to bomb the tunnel and other New York City landmarks.
Sheik Gulshair, who denied any affiliation with terrorists, retired from service to the Saudi government in 1995 and moved his wife and six children to Miramar, southwest of Fort Lauderdale, where he had been given a small stipend to run the Masid al Hijra Mosque.
By the late 1990s, some of his followers had attracted the attention of the FBI's counterterrorism squad in Miami. One of them was his eldest son, Adnan.
Adnan was born in June 1975 in either Saudi Arabia or Guyana. After the family moved to Florida, he attended Broward Community College, where he excelled in chemistry and biology, as well as computers, according to the FBI.
He also suffered from asthma, which required him to use an inhaler, his mother said in a recent interview. As a result, he often remained indoors, she said, tending to his studies, his computer business and his scholarly work.
Sometime in the late 1990s, Shukrijumah started leaning toward more radical Islamist views, authorities say. The FBI believes he was inspired by a group of Muslim men in South Florida who gave him books and videotapes about jihad in Bosnia-Herzegovina, Kashmir and Afghanistan.
In late 1999, Shukrijumah began traveling to Pakistan and Afghanistan. To get into an Al Qaeda training camp, he needed a sponsor. The FBI says Shukrijumah found one in Ismael Faiz of Lahore, Pakistan. U.S. officials believe Faiz is a member of Al Qaeda and the Pakistani militant group Lashkar-e-Taiba, which has been connected to recent alleged terrorist plots in Canada and London.
At the camps, Shukrijumah was initially rejected for training. Instead, he started at the bottom, doing dishes and menial work before earning the right to train with weapons and tactics, agents say.
He had trouble getting along with fellow trainees. Shukrijumah was said to be "difficult to work with: temperamental, confident in his ability to the point of being egocentric," said a senior FBI official close to the investigation.
His mother attributes his headstrong personality to his having to assume a father-figure role to his younger siblings because Sheik Gulshair was away so often doing missionary work.
After he started traveling to Pakistan and Afghanistan, however, Shukrijumah began to change, say friends and associates interviewed by the FBI. He would take off for long periods, to places overseas he would not discuss.
"Every time he came back, he was a different person," the FBI official said. "He was more calm, more cool and more purposeful in his actions."
By 2001, the FBI was investigating Shukrijumah in connection with two suspected terrorist plots, one of which involved a group apparently using South Florida as a base from which to recruit militants and finance attacks and assassinations in the Middle East.
But agents were never able to connect him to either plot. They later came to believe that he had been deliberately keeping his distance because, as one agent put it, "it was felt in the [Al Qaeda] community that he was in for bigger and better things."
After the Sept. 11 attacks, federal agents swarmed South Florida looking for clues and connections they might have missed. As many as 15 of the hijackers had spent their last months there, training for and planning the suicide mission.
The FBI ultimately took several of Shukrijumah's acquaintances into custody on terrorism or immigration charges.
Agents also went looking for Shukrijumah. But by then, he was gone and had left few clues.
'He Could Be Anywhere'
When Shukrijumah reemerged in the FBI's consciousness in March 2003, Pasquale "Pat" D'Amuro, then the FBI's senior counter-terrorism official and a veteran Al Qaeda tracker, felt an acute sense of dread.
"We thought he was a grave danger to the security of the United States," D'Amuro recalled recently. "We thought he could be anywhere."
On March 20, 2003, the same day the U.S. began bombing Iraq, the FBI went public. With TV news crews on their heels, more than 50 federal agents and local police officers descended on Shukrijumah's neighborhood.
Armed with a warrant for his arrest as a material witness, FBI agents knocked on doors, showing photographs and asking whether he had been seen in Florida recently.
They scoured his mail, credit cards, bank records and phone bills.
By then, however, Shukrijumah had been away from his family home for almost two years.
In the months before Sept. 11, he had traveled widely through the United States and Canada, scouting potential terrorist targets, say FBI officials, who believe he spent about a week each in New York, Washington, Chicago and Montreal.
Since the attacks, her son had called just once, to check in, Zuhrah Abdu Ahmed told the agents.
The agents asked whether her son knew lead hijacker Mohamed Atta and others she had seen on TV. They wanted to know whether he had ever mentioned Al Qaeda or trips to Pakistan and Afghanistan.
Ahmed said her memory was hazy, but she insisted that her son was innocent.
Sitting on the front stoop of the family home, Ahmed -- a tiny woman with warm brown eyes and a big smile, dressed in a flowing black robe and head scarf -- said her son didn't like South Florida's freewheeling singles scene and the nightclubs and bikinis.
"But he like America so much," she said. "People, he say, [are] very nice and kind. If only they more decent, he say, this would be the best place on Earth."
Ahmed, whose husband died in 2004, conceded that it was possible her son might have fallen in with the wrong crowd.
"I recognize a lot of people do evil stuff in the name of the religion," she said, and then paused. "He's a young guy. Maybe they try to trap him, without he even knew what was going on around him. Who knows?"
The FBI also began chasing Shukrijumah through the back alleys of cyberspace. Within hours of the FBI's public announcement, Shukrijumah might have given them a lead.
Just after midnight that day, an e-mail popped up in the guestbook section of MasterArabic.com, a website that Shukrijumah had set up to promote his father's Arabic tutoring business and Islamic teachings. Routed to obscure the identity of the sender, the message said only, "I am safe."
Tracking Down Leads
In their hunt for Shukrijumah, the FBI dispatched teams of agents to Saudi Arabia, Morocco and Yemen, where he had relatives. Agents also tracked leads through Europe, Asia and South America.
One of those leads took them to Charlieville, Trinidad, where a Muslim cleric had called federal agents to say Shukrijumah was traveling to and from the island and "had company." Agents fanned out across the dirt streets of Charlieville and found several men Shukrijumah had spent time with.
One of them, Imtiaz Mohammed, told The Times recently that he had two lengthy, sometimes testy, interviews with FBI agents. He told them that he, Shukrijumah and others in Trinidad did talk about world politics, but that Shukrijumah never said anything suggesting he was a militant, and never explained his travels.
In March 2004, after a year of inconclusive leads, the FBI got wind of a Shukrijumah sighting. Intelligence had placed him at a summit of the so-called second-generation Al Qaeda leaders in the rugged mountains of Waziristan, an area along the Pakistan-Afghanistan border where much of the Al Qaeda brain trust -- including Osama bin Laden -- was believed to be hiding.
Working together, authorities in Pakistan, Britain and the United States arrested some of the attendees and seized several computers.
The evidence indicated the attendees were discussing future terrorist operations in Europe and the U.S. At least one had compiled video footage of the New York Stock Exchange, a Newark, N.J., insurance building and the World Bank and International Monetary Fund buildings in Washington.
On May 26, 2004, Atty. Gen. John Ashcroft went public again, singling out Shukrijumah as the most dangerous of seven Al Qaeda operatives suspected of planning strikes in the U.S.
Citing "credible intelligence from multiple sources," Ashcroft described Shukrijumah as "a clear and present danger" who might be trying to enter the country.
More tips and rumors continued to pour in. Most were maddeningly vague. They persisted through the elections in November, but nothing ever happened.
Then Shukrijumah appeared to drop off the radar screen again. There hasn't been a publicly disclosed sighting since.
Nearly two years later, senior FBI and intelligence officials say they still debate where Shukrijumah might be. Their best guess is that he remains in Waziristan.
In July, the U.S. government, which is offering a $5-million reward, began handing out fancy green matchboxes in Pakistan bearing a photograph of Shukrijumah.
"You give us Adnan G. el Shukrijumah and in return we will give you rewards," the boxes say in Urdu and Pashto. "We assure you that all information would be kept secret."
Meanwhile, Shukrijumah continues to cause many a sleepless night.
Special Agent Andrew Lenzen, the lead case agent and a veteran of the FBI's Miami counter-terrorism squad, has amassed an encyclopedic knowledge of Shukrijumah's actions and personality quirks. He has even compiled a timeline of his life, beginning with the day he was born.
"I know him almost like his mother," said Lenzen. "I've lived, slept and dreamed him for the past three years."