Federal law enforcement officials are trying to determine whether Nidal Malik Hasan communicated with terrorists or a radical cleric who used to preach at a northern Virginia mosque before waging Thursday's massacre.

Investigators are trying to figure out whether the Army psychiatrist kept in touch with Anwar Al-Awlaki, who was the spiritual leader at the Dar Al-Hijrah mosque in Falls Church in 2001. Hasan reportedly attended the mosque at that time. Awlaki left the U.S. for Yemen in 2002 where he is a vocal supporter of terrorism.

Hasan, who reportedly defended suicide bombings, was chastised for proselytizing to his patients about Islam and shouted Allahu Akhbar before opening fire Thursday, killed 13 people and wounded 30 others before being shot by responding police officers.

Regardless of the depth of any relationship, Awlaki is out with a posting hailing Hasan as "a hero" who followed duty to his faith above his nation:

"Nidal Hassan is a hero. He is 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. This is a contradiction that many Muslims brush aside and just pretend that it doesn't exist. Any decent Muslim cannot live, understanding properly his duties towards his Creator and his fellow Muslims, and yet serve as a US soldier. The US is leading the war against terrorism which in reality is a war against Islam. Its army is directly invading two Muslim countries and indirectly occupying the rest through its stooges.

Nidal opened fire on soldiers who were on their way to be deployed to Iraq and Afghanistan. How can there be any dispute about the virtue of what he has done? In fact the only way a Muslim could Islamically justify serving as a soldier in the US army is if his intention is to follow the footsteps of men like Nidal."

Awlaki's view that the war on terrorism is a war on Islam is one echoed by American Islamist groups considered to be mainstream. For examples, see here, here and here.

According to the Telegraph, which first reported Hasan's ties to Dar Al-Hijrah, "Hasan's eyes 'lit up' when he mentioned his deep respect for al-Awlaki's teachings, according to a fellow Muslim officer at the Fort Hood base in Texas."

ABC, meanwhile, cites two anonymous government officials who have been briefed on the case saying intelligence agencies learned "months ago" that Hasan tried to contact with people associated with al Qaeda. Investigators are said to be scouring Hasan's computer and trying to identify all his email accounts to see whether he communicated with terrorists in advance of his shooting spree.

The Washington Post reports Awlaki is among the prospective contacts. He previously was scrutinized after two other men who prayed at Dar Al-Hijrah were identified as 9/11 hijackers Khalid Almidhar and Nawaf Alhazmi.

Awlaki was investigated by the FBI before he left the country but never was charged with any crime.

For more on the Fort Hood investigation and on Awlaki, click here, here and here.