IAMI, March 21 — As state and federal law enforcement officials followed leads from South Florida to Morocco in an extensive search for a suspected operative of Al Qaeda, the man's family insisted that the authorities were looking for the wrong person.The family of Adnan G. el-Shukrijumah has been holed up in its modest, single-family home in a working-class neighborhood of Miramar, near Fort Lauderdale, since almost immediately after the Federal Bureau of Investigation posed a worldwide bulletin on Thursday declaring Mr. Shukrijumah, 27, an "imminent threat" who could be planning a terrorist attack on the United States. Late this...