After the shooting, the FBI is doing a new assessment - of its own conduct.
The Army psychiatrist is believed to have acted alone despite repeated communications - intercepted by authorities - with a radical imam overseas, U.S. officials said Monday. The FBI will conduct an internal review to see whether it mishandled early information about the man accused in the bloody rampage that killed 13 people and wounded 29.
President Barack Obama was joining grieving families and comrades of the victims Tuesday at a memorial service at the sprawling Texas Army base. Hasan, awake and talking to doctors, met his lawyer Monday in the San Antonio hospital where he is recovering, under guard, from gunshot wounds in the assault.
In Washington, an investigative official and a Republican lawmaker said Hasan had communicated 10 to 20 times with Anwar al-Awlaki, an imam released from a Yemeni jail last year who has used his personal Web site to encourage Muslims across the world to kill U.S. troops in Iraq. Despite that, no formal investigation was opened into Hasan, they said.
Investigative officials spoke on condition of anonymity because they were not authorized to discuss the case. Republican Rep. Pete Hoekstra of Michigan, the top Republican on the House Intelligence Committee, said it was his understanding Hasan and the imam exchanged e-mails that counterterrorism officials picked up.
Officials said Hasan will be tried in a military court, not a civilian one, a choice that suggests his alleged actions are not thought to have emanated from a terrorist organization.
Meanwhile, The Washington Post reported Tuesday that Hasan warned his medical colleagues a year and a half ago that to "decrease adverse events" the U.S. military should allow Muslim soldiers to be released as conscientious objectors instead of fighting in wars against other Muslims. Hasan, an Army psychiatrist, made the recommendation in a culminating presentation to senior Army doctors at Walter Reed Medical Center, where he spent six years as an intern, resident and fellow before being transferred to Fort Hood.
"It's getting harder and harder for Muslims in the service to morally justify being in a military that seems constantly engaged against fellow Muslims," Hasan said in the presentation, a copy of which was obtained by the Post.
FBI Director Robert Mueller ordered the inquiry into the bureau's handling of the case, including its response to potentially worrisome information gathered about Hasan beginning in December 2008 and continuing into early this year.
Based on all the investigations since the attack, the investigators said they have no evidence that Hasan had help or outside orders in the shootings.
Even so, they revealed the major had once been under scrutiny from a joint terrorism task force because of the series of communications going back months. Al-Awlaki is a former imam at a Falls Church, Va., mosque where Hasan and his family occasionally worshipped.
In 2001, al-Awlaki, a native-born U.S. citizen, had contact with two of the Sept. 11 hijackers, and on Monday his Web site praised Hasan as a hero.
Military officials were made aware of communications between Hasan and al-Awlaki, but because the messages did not advocate or threaten violence, civilian law enforcement authorities could not take the matter further, the officials said. The terrorism task force concluded Hasan was not involved in terrorist planning.
Officials said the content of those messages was "consistent with the subject matter of his research," part of which involved post-traumatic stress disorder stemming from U.S. combat operations in Iraq and Afghanistan.
A law enforcement official said the communications consisted primarily of Hasan posing questions to the imam as a spiritual leader or adviser, and the imam did respond to at least some of those messages.
No formal investigation was ever opened based on the contacts, the officials said.
They said the decision to bring military charges instead of civilian criminal charges against Hasan did not mean it wasn't a terrorism case. But it is likely authorities would have had more reason to take the case to federal court if they had found evidence Hasan acted with the support or training of a terrorist group.
Investigators tried to interview Hasan on Sunday at the military hospital where he is being held, but he refused to answer and requested a lawyer, the officials said.
Hasan's new civilian and military attorneys met him for about half an hour at Brooke Army Medical Center in San Antonio, said retired Col. John P. Galligan, who was hired by Hasan's family. Galligan said Hasan asked for an attorney even though he is on sedatives and his condition is guarded.
"Given his medical condition, that's the smart move," Galligan told The Associated Press on Monday night. "Nobody from law enforcement will be questioning him."
Galligan said both he and Maj. Christopher E. Martin, Fort Hood's senior defense attorney, met Hasan. Galligan questioned whether Hasan can get a fair trial at Fort Hood, given Obama's visit to the base and public comments by the post commander, Lt. Gen. Robert Cone. Galligan also said he plans to raise the issue of Hasan's mental condition.
The most serious charge in military court is premeditated murder, which carries the death penalty.
The Army has not yet appointed a lead prosecutor in the case, said Fort Hood spokesman Tyler Broadway.
Associated Press writers Angela K. Brown at Fort Hood and Pamela Hess in Washington contributed to this report.