The investigation is focused on a naturalized U.S. citizen, originally from Pakistan, who became the target of an undercover sting operation, the sources said. An administration official said the man drew the attention of law enforcement officials by seeking to obtain unspecified materials. The planned attack was not imminent, the sources said, speaking on the condition of anonymity because the matter remains under investigation.
The man, Farooque Ahmed, 34, of Ashburn, is believed to have conceived of the plot and planned to carry it out on his own. It is not known how far he proceeded in his preparations.
Ahmed was expected to appear at a hearing scheduled for 2 p.m. at the U.S. District Court in Alexandria. He was arrested in Herndon.