U.S. military doctors overseeing Nidal Malik Hasan's medical training were concerned he was "psychotic" and possibly capable of killing other American soldiers, before the Army major allegedly went on a deadly shooting rampage at Fort Hood, Texas.

Psychiatrists and medical officials at Walter Reed Army Medical Center held a series of meetings beginning in the Spring of 2008 to discuss serious concerns about his work and behavior, National Public Radio reported.

One of the questions they asked: Was Hasan psychotic?

"Put it this way," one official told NPR. "Everybody felt that if you were deployed to Iraq or Afghanistan, you would not want Nidal Hasan in your foxhole."

One official who participated in the discussions reportedly told others he was worried that if Hasan was deployed to Iraq or Afghanistan, he might leak covert military information to Islamic extremists, NPR reported.

Another official "wondered aloud" to colleagues whether Hasan might be capable of killing fellow soldiers in the same way a Muslim sergeant in 2003 had set off grenades at a base in Kuwait, killing two and wounding 14, the radio network reported.

The officials who discussed Hasan's status were unaware — as some top Walter Reed hospital officials were — that intelligence agencies had been tracking Hasan's e-mails to a radical imam since December 2008, NPR said.

Officials considered kicking Hasan out of the program but chose not to partly because firing a doctor is a "cumbersome and lengthy" process that involves hearings and potential legal conflict, sources told NPR.

Officials also believed they lacked solid evidence that Hasan was unstable and were concerned they could be accused of discriminating against him because of his Islamic identity or views.

The concerns about Hasan's performance and religious views were shared with other military officials considering his assignment after he finished his medical training, and the consensus was to send the 39-year-old psychiatrist to Fort Hood, an official told the Associated Press.

Hasan was characterized in the meetings as a mediocre student and lazy worker, a matter of concern among the doctors and staff at Walter Reed and the Uniformed Services University of the Health Sciences, a military medical school in Bethesda, Maryland, an official told The Associated Press.

Fort Hood, one of the country's largest military installations, was considered the best assignment for Hasan because other doctors could handle the workload if he continued to perform poorly and his superiors could document any continued behavior problems, the official said.

Sharon Willis, a spokeswoman for the Uniformed Services University, referred questions Wednesday about Hasan to his lawyer. The attorney, John Galligan of Belton, Texas, did not immediately return a telephone call seeking comment.

The revelations about the concerns that Hasan's superiors had before sending him to Fort Hood come amid a growing debate over what warning signs the military and law enforcement officials might have missed before last week's massacre.

A joint terrorism task force overseen by the FBI learned late last year of Hasan's repeated contact with a radical Muslim cleric who encouraged Muslims to kill U.S. troops in Iraq. The FBI said in a statement late Wednesday that the task force did not refer early information about Hasan to superiors because it concluded he wasn't linked to terrorism.

The doctors and staff who discussed concerns about Hasan had several group conversations about him that started in early 2008 during regular monthly meetings and ended as he was finishing a fellowship in disaster and preventive psychology this summer, the official familiar with the discussions said.

They saw no signs of mental problems, no risk factors that would predict violent behavior. And the group discussed other factors that suggested Hasan would continue to thrive in the military, factors that mitigated their concerns, the official said.

According to the official, records reviewed by Hasan's superiors described nearly 20 years of military service, including nearly eight years as an enlisted soldier; completion of three rigorous medical school programs, albeit as a student the group characterized in their discussions as mediocre; his resilience after the deaths of his parents early in his medical education, and an otherwise polite and gentle nature when not discussing religion.

The Army has said it has no record of enlisted service for Hasan, instead noting that his military service began when he started the medical school program in 1997.

The official said the group became increasingly concerned about Hasan's religious views after he completed two research projects that took a decidedly religious tone — one at the end of his residency at Walter Reed that advocated allowing Muslim soldiers to be released as conscientious objectors instead of fighting in wars against other Muslims, and the other as he pursued his master's degree in public health that discussed religious conflicts for Muslim U.S. soldiers.

Some in the group shared their experiences with Hasan, all telling similar stories about repeated instances when he made religion an issue.

Officials involved at various times in the meetings about Hasan included John Bradley, Walter Reed's chief of psychiatry; Scott Moran, Walter Reed's psychiatric residency program director; Robert Ursano, chairman of the Uniformed Services University's psychiatry department; Charles Engel, the university's assistant chair of psychiatry, and David Benedek, an associate professor of psychiatry at the university.

Those officials either declined to comment or did not return telephone calls and e-mails seeking comment Wednesday.

Meanwhile, the Pentagon has found no evidence that Hasan formally sought release from the Army as a conscientious objector or for any other reason, two senior military officials told The Associated Press. Family members have said he wanted to get out of the Army and had sought legal advice, suggesting that Hasan's anxiety as a Muslim over his pending deployment overseas might have been a factor in the deadly rampage.

Hasan had complained privately to colleagues that he was harassed for his religion and that he wanted to get out of the Army. But there is no record of Hasan filing a complaint with his chain of command regarding any harassment he may have suffered for being Muslim or any record of him formally seeking release from the military, the officials told the AP.

The officials spoke on condition of anonymity because the case is under investigation.

Another Army official, Lt. Col. George Wright, said Wednesday that Hasan likely would have had to commit to another year in the military when he was transferred to Fort Hood earlier this summer. It is common for an officer to incur a one-year service extension when they receive a transfer to another post.

The Associated Press contributed to this report.