A standard question asked of al-Qaeda suspects being held overseas is this: What person still at large do you regard as the most likely to harm the U.S. or U.S. interests? It was the frequency with which one name, Adnan G. el-Shukrijumah, popped up that led the FBI to launch an all-out search for the 27-year-old Saudi. "A number of people concurred that he was the individual perceived to be the most dangerous," a Justice Department official said. But sources tell TIME that el-Shukrijumah has long been in the FBI's sights, though investigators only recently matched up his photo and aliases with his true identity. He was known to be friends with Imran Mandhai, who pleaded guilty last year to plotting to blow up a National Guard armory and electrical-power stations in Florida, and el-Shukrijumah's name has surfaced in investigations of other terrorist episodes. Agents first questioned his family in Miramar, Fla., shortly after 9/11 and have since visited half a dozen times. Now the FBI is looking into his connection to other terrorist plots.
El-Shukrijumah studied computer engineering in Florida and, according to the FBI, logged time at an al-Qaeda training camp in Afghanistan. Members of Broward County's Islamic community told TIME that he kept mostly to himself at area mosques but would join in radical speeches condemning infidels. His father used similar invective in services at the mosque he ran next to the family's house, they said. In an interview, el-Shukrijumah's father insisted that he taught his son only "peaceful values." --By Timothy J. Burger, Viveca Novak, Michael Weisskopf and Tim Padgett