The radical Muslim imam who ministered to at least three Sept. 11 hijackers, the Fort Hood shooter and the Nigerian accused of trying to blow up a U.S. jet on Christmas Day, was taken into custody at New York's JFK Airport on a felony arrest warrant in 2002.

Even though Anwar al-Awlaki had been on the FBI's radar for years, he was let go, most likely because of intervention by Saudi Arabia, classified documents and interviews reveal. Now he continues to train new "martyrs" in Yemen.

"We were stunned" that he was let go, said Ray Fournier, a federal agent who has been tracking Awlaki as part of a joint terrorism task force. "He was a high-value target. Everybody was excited about the prospect of hooking this guy up under a [criminal] charge to motivate a conversation with him regarding his relationship with the [Sept. 11] hijackers."

Awlaki, 38, was born in New Mexico and raised as a teen in Yemen. Fournier, then a Diplomatic Security Service agent, discovered that he lied about his place of birth on an application for a U.S. Agency for International Development grant, receiving $20,000 a year to attend engineering classes at Colorado State University in the early 1990s. Awlaki turned to radical Islam instead, preaching at mosques in Fort Collins, Colo., and San Diego.

He attracted the FBI's attention in 1999, because of alleged contact with an Al Qaeda agent who bought a satellite phone for Usama bin Laden. But the investigation was closed the next year because of lack of evidence.

While in San Diego, Fournier said, Awlaki met at his mosque with Nawaf al-Hazmi and Khalid al-Mihdhar, who would go on to hijack the plane that was crashed into the Pentagon on Sept. 11.

"They weren't discussing tabouli recipes," said Fournier, who believes Awlaki knew of the 9/11 plot in advance.

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