Fort Hood suspect's links to imam under scrutiny

Sen. Joseph I. Lieberman (I-Conn.), chairman of the Senate Homeland Security and Governmental Affairs Committee, said he planned an investigation to determine whether the shootings constituted a terrorist attack and whether the Army missed warning signs about Hasan's ideological views. The House Armed Services and intelligence committees are also likely to investigate, an official said.

Investigators, intelligence analysts and forensic psychologists remain particularly keen on conducting their own psychological assessment of Hasan. A key to understanding his possible motive will be piecing together accounts from co-workers and neighbors, as well as his own writings, to determine the relationship between his emotional state and any attraction to more militant ideologies, even those justifying suicide attacks, officials said.

Hasan, 39, the unmarried child of Palestinian immigrants who was born in Arlington, attended Dar al-Hijrah at the time of his mother's May 2001 death, an event that acquaintances said led to his increased religiosity. In recent years, he worshipped regularly at the Muslim Community Center in Silver Spring, which is regarded as moderate.

People who know him have said that his alleged actions at Fort Hood may have been triggered by a number of factors, including the Sept. 11 attacks and the U.S.-led invasions of Iraq and Afghanistan, Hasan's counseling of returning veterans with psychiatric problems, reported anti-Muslim harassment from Army colleagues and his moral doubts about his upcoming deployment to Afghanistan.

Aulaqi has been identified as a spiritual adviser of 9/11 hijackers Khalid Almihdhar and Nawaf Alhazmi; the 9/11 Commission Report and a subsequent congressional report noted that they met with Aulaqi at a mosque in San Diego in 2000 and after he moved to Dar al-Hijrah in 2001.

The FBI investigated Aulaqi nearly a decade ago, after he briefly served as vice president of the U.S. branch of a Yemeni charity that federal prosecutors later described as a front organization used to support al-Qaeda and Osama bin Laden. The FBI learned that he also may have been contacted by a bin Laden "procurement agent," who served as fundraiser for a charity that the Treasury Department designated a bin Laden financier, and said that Aulaqi's group was its Yemeni partner.

The FBI also learned that Aulaqi was visited in early 2000 by a close associate of Omar Abdel Rahman, the man known as "the blind sheik" who was convicted in connection with the 1993 World Trade Center bombing. But the FBI reported that it did not have reason to prosecute or detain Aulaqi, who left the United States in 2002 and has lived in Yemen since 2004.

Yemeni authorities detained him in mid-2006 at the request of the U.S. government, then released him at the end of 2007. Since then, Britain has barred him from speaking there, and U.S. authorities have called him an al-Qaeda supporter who has worked with its networks in the Persian Gulf and plotted attacks against the United States and its allies.

Aulaqi "targets U.S. Muslims with radical online lectures encouraging terrorist attacks from his new home in Yemen," Charles Allen, then-chief intelligence officer for the Homeland Security Department, said in October 2008, calling him an "example of al-Qaeda reach into" the United States."

Aulaqi "speaks to North Americans better than anybody else" overseas, Allen added in an interview. Aulaqi's listeners include small extremist elements in the United States and Canada, including at least one Somali American youth from Minneapolis who joined al-Shabab, an extremist Islamist insurgent group that has pledged fealty to bin Laden.

Current and former lawmakers, including former Senate intelligence committee chairman Bob Graham, who led the congressional inquiry into the Sept. 11 attacks, have accused the FBI of bungling investigations of Aulaqi before and after the strikes.

But investigators are being cautious and pragmatic. Hasan's contacts a decade ago at a mosque attended by thousands may not prove meaningful. Similarly, people may hear fiery rhetoric or extremist views from a pulpit or online but may not be motivated to act on it.

Still, terrorism experts say they expect future cases of conflicted individuals who become radicalized and take up violence. "I don't see any conspiracy, and I don't see at this stage any real tie to 9/11 per se," Allen said. However, he added, Hasan "seems to me to be very much a self-radicalized or inspired individual. . . . I feel this will be our problem over the next five years."

Staff writers Joby Warrick, Ben Pershing, Mary Beth Sheridan and Ann Scott Tyson contributed to this report.