Later today, Farooque Ahmed, the Virginia man charged with plotting to bomb several Metrorail stations, appears in federal court in Alexandria, Va., for a detention hearing.
Sources involved in the investigation, speaking to the Associated Press on condition of anonymity, say a contact inside the Muslim community first tipped off the FBI that Ahmed was asking around, trying to join a terrorist group and kill Americans overseas.
Investigators believe Ahmed became radicalized in the United States, making him the latest in a string of U.S. citizens charged with plotting terrorist attacks in this country.
In April, Ahmed thought he had found what he wanted: a pair of al-Qaida operatives who would help him carry out a bomb attack on the nation's second-busiest subway system, according to court documents unsealed Thursday.
But the operatives were really undercover investigators. According to police, the meetings at local hotels were all staged with the FBI's cameras rolling.
What followed was an elaborate ruse in which Ahmed was given intelligence-gathering duties and coded information in a Quran as part of the supposed plot to kill commuters at Metro stations.
Ahmed faces up to 50 years in prison if convicted.