Fort Hood shooter Nidal Malik Hasan was investigated by the FBI after intelligence agencies intercepted at least 18 e-mails between him and al-Awlaki between December 2008 and June 2009.
Even before the contents of the e-mails were revealed, terrorism expert Jarret Brachman said that Hasan's contacts with al-Awlaki should have raised "huge red flags", because of his influence on radical English-speaking jihadis.
Charles Allen, no longer in government, noted that there was no work-related reason for Hasan to be in touch with al-Awlaki.
Former CIA officer Bruce Riedel opined: "E-mailing a known al-Qaeda sympathizer should have set off alarm bells.
Even if he was exchanging recipes, the bureau should have put out an alert."
A DC-based Joint Terrorism Task Force operating under the FBI was notified of the e-mails and reviewed the information.
Army employees were informed of the e-mails, but they didn't perceive any terrorist threat in Hasan's questions.
Instead, they viewed them as general questions about spiritual guidance with regard to conflicts between Islam and military service and judged them to be consistent with legitimate mental health research about Muslims in the armed services.
The assessment was that there was not sufficient information for a larger investigation.
In one of the e-mails, Hasan wrote al-Awlaki: "I can't wait to join you [in the afterlife]". "
It sounds like code words," said Lt.
Col.
Tony Shaffer, a military analyst at the Center for Advanced Defense Studies. "
That he's actually either offering himself up, or that he's already crossed that line in his own mind."

Yemeni journalist Abdulelah Hider Shaea interviewed al-Awlaki in November 2009.
Al-Awlaki acknowledged his correspondence with Hasan.
He said he "neither ordered nor pressured ... Hasan to harm Americans."
Al-Awlaki said Hasan first e-mailed him December 17, 2008, introducing himself by writing: "Do you remember me?
I used to pray with you at the Virginia mosque."
Hasan said he had become a devout Muslim around the time al-Awlaki was preaching at Dar al-Hijrah, in 2001 and 2002, and al-Awlaki said 'Maybe Nidal was affected by one of my lectures.'"
He added: "It was clear from his e-mails that Nidal trusted me.
Nidal told me: 'I speak with you about issues that I never speak with anyone else.'"
Al-Awlaki said Hasan arrived at his own conclusions regarding the acceptability of violence in Islam and said he was not the one to initiate this.
Shaea said, "Nidal was providing evidence to Anwar, not vice versa."

Asked whether Hasan mentioned Fort Hood as a target in his e-mails, Shaea declined to comment.
Al-Awlaki said the shooting was acceptable in Islam, however, because it was a form of jihad, as the West began the hostilities with the Muslims.
Al-Awlaki said he "blessed the act because it was against a military target.
And the soldiers who were killed were ... those who were trained and prepared to go to Iraq and Afghanistan".

Al-Awlaki's e-mail conversations with Hasan were not released, and he was not placed on the FBI Most Wanted list, indicted for treason, or officially named as a co-conspirator with Hasan.
The U.S. government was reluctant to classify the Fort Hood shooting as a terrorist incident, or identify any motive.
 The Wall Street Journal reported in January 2010 that al-Awlaki had not "played a direct role" in any of the attacks, and noted he had never been charged with a crime in the US.

One of his fellow officers at Fort Hood said Hasan was enthusiastic about al-Awlaki.
Some investigators believe al-Awlaki's teachings may have been instrumental in Hasan's decision to stage the attack.
On his now-disabled website, al-Awlaki praised Hasan's actions, describing him as a hero.
Fort Hood shooter Nidal Malik Hasan was investigated by the FBI after intelligence agencies intercepted at least 18 e-mails between him and al-Awlaki between December 2008 and June 2009. Even before the contents of the e-mails were revealed, terrorism expert Jarret Brachman said that Hasan's contacts with al-Awlaki should have raised "huge red flags", because of his influence on radical English-speaking jihadis. Charles Allen, no longer in government, noted that there was no work-related reason for Hasan to be in touch with al-Awlaki. Former CIA officer Bruce Riedel opined: "E-mailing a known al-Qaeda sympathizer should have set off alarm bells. Even if he was exchanging recipes, the bureau should have put out an alert." A DC-based Joint Terrorism Task Force operating under the FBI was notified of the e-mails and reviewed the information. Army employees were informed of the e-mails, but they didn't perceive any terrorist threat in Hasan's questions. Instead, they viewed them as general questions about spiritual guidance with regard to conflicts between Islam and military service and judged them to be consistent with legitimate mental health research about Muslims in the armed services. The assessment was that there was not sufficient information for a larger investigation. In one of the e-mails, Hasan wrote al-Awlaki: "I can't wait to join you [in the afterlife]". "It sounds like code words," said Lt. Col. Tony Shaffer, a military analyst at the Center for Advanced Defense Studies. "That he's actually either offering himself up, or that he's already crossed that line in his own mind."
Yemeni journalist Abdulelah Hider Shaea interviewed al-Awlaki in November 2009. Al-Awlaki acknowledged his correspondence with Hasan. He said he "neither ordered nor pressured ... Hasan to harm Americans." Al-Awlaki said Hasan first e-mailed him December 17, 2008, introducing himself by writing: "Do you remember me? I used to pray with you at the Virginia mosque." Hasan said he had become a devout Muslim around the time al-Awlaki was preaching at Dar al-Hijrah, in 2001 and 2002, and al-Awlaki said 'Maybe Nidal was affected by one of my lectures.'" He added: "It was clear from his e-mails that Nidal trusted me. Nidal told me: 'I speak with you about issues that I never speak with anyone else.'" Al-Awlaki said Hasan arrived at his own conclusions regarding the acceptability of violence in Islam and said he was not the one to initiate this. Shaea said, "Nidal was providing evidence to Anwar, not vice versa."
Asked whether Hasan mentioned Fort Hood as a target in his e-mails, Shaea declined to comment. Al-Awlaki said the shooting was acceptable in Islam, however, because it was a form of jihad, as the West began the hostilities with the Muslims. Al-Awlaki said he "blessed the act because it was against a military target. And the soldiers who were killed were ... those who were trained and prepared to go to Iraq and Afghanistan".
Al-Awlaki's e-mail conversations with Hasan were not released, and he was not placed on the FBI Most Wanted list, indicted for treason, or officially named as a co-conspirator with Hasan. The U.S. government was reluctant to classify the Fort Hood shooting as a terrorist incident, or identify any motive.  The Wall Street Journal reported in January 2010 that al-Awlaki had not "played a direct role" in any of the attacks, and noted he had never been charged with a crime in the US.
One of his fellow officers at Fort Hood said Hasan was enthusiastic about al-Awlaki. Some investigators believe al-Awlaki's teachings may have been instrumental in Hasan's decision to stage the attack. On his now-disabled website, al-Awlaki praised Hasan's actions, describing him as a hero.
Anwar al-Awlaki