WASHINGTON — In a series of conversations in Qaeda safe houses in Yemen in 2009, Anwar al-Awlaki carefully sized up a young Nigerian volunteer, decided the man had the diligence and dedication for a “martyrdom mission” and finally unveiled what he had in mind.

Mr. Awlaki, an American-born cleric who had become a leading propagandist for Al Qaeda, told the man, Umar Farouk Abdulmutallab, that “the attack should occur on board a U.S. airliner,” according to the account Mr. Abdulmutallab gave the Federal Bureau of Investigation.

Mr. Abdulmutallab told F.B.I. agents that he “was resolved to killing innocent people and considered them to be ‘collateral damage.’” With “guidance” from Mr. Awlaki, he said, he had “worked through all these issues.”

Newly released documents, obtained by The New York Times after a two-year legal battle under the Freedom of Information Act, fill in the details of a central episode in the American conflict with Al Qaeda: Mr. Abdulmutallab’s recruitment by Mr. Awlaki and his failed attempt to blow up an airliner approaching Detroit on Christmas in 2009 using sophisticated explosives hidden in his underwear.

Read the whole story from The New York Times.

Featured image courtesy of ABC News.