As officials advance the investigation into the Army Major who allegedly perpetrated last week's massacre at Fort Hood , attention is turning to Anwar al Awlaki, a top al Qaeda recruiter who was in contact with Major Nidal Malik Hasan before last week's shootings.
Awlaki, a charismatic American Muslim imam, now operates a jihadist web site out of Yemen that calls on all Muslims to wage war against the U.S. Officials say Hasan had between 10 and 20 contacts with Awlaki beginning late last year.
U.S. intelligence agencies were aware months ago that Hasan was attempting to make contact with Awlaki, two American officials briefed on classified material in the case told ABC News.
According to the officials, the Army was informed of Hasan's contact, but it is unclear what, if anything, the Army did in response.
"Awlaki is known as a senior recruiter for al Qaeda," former FBI agent Brad Garrett, now an ABC News consultant, told Nightline. "He would be the spiritual motivator. Almost like someone you would go to and say, 'this is what I'm thinking about doing.' And they join in and encourage you and basically help you rationalize your behavior."
On Wednesday, a new blog entry on Awlaki's site praised Hasan as a "hero" and a "man of conscience who could not bear living the contradiction of being a Muslim and serving in an army that is fighting against his own people."
Before moving to Yemen, Awlaki was the imam of a Falls Church, Virginia mosque that was attended by Hasan and two of the 9/11 hijackers.
Much of his writings now glorify violence and suicide, issues members of Congress say should have been identified early on.
"If this guy is in contact with American citizens, it is something that should have raised major red flags," said Congressman Peter Hoekstra, (R-MI), the ranking Republican on the House Intelligence Committee.
According to his site, Awlaki served as an imam in Denver, San Diego and Falls Church, Virginia.
The Associated Press reported Sunday that Major Hasan attended the Falls Church mosque when Awlaki was there.
The Telegraph of London reported that Awlaki had made contact with two of the 9/11 hijackers when he was in San Diego.
He denied any knowledge of the hijacking plot and was never charged with any crime. After an intensive investigation by the FBI, Awlaki moved to Yemen. He was imprisoned in Yemen in 2006, and after his release his message became more radical.
A fellow Army doctor who studied with Hasan, Val Finell, told ABC News, "He would frequently say he was a Muslim first and an American second. And that came out in just about everything he did at the University."
Finell said he and other Army doctors complained to superiors about Hasan's statements.
"And we questioned how somebody could take an oath of office…be an officer in the military and swear allegiance to the constitution and to defend America against all enemies, foreign and domestic and have that type of conflict," Finell told ABC News.
The Army Chief of Staff, General George Casey, raised concerns over the weekend that innocent Muslim soldiers could suffer as a result of the shooting at Fort Hood.
"I think the speculation (on Hasan's Islamic roots) could potentially heighten backlash against some of our Muslim soldiers," he said on ABC's "This Week."