Hasan, 39, was flown to Brooke Army Medical Center at Fort Sam Houston on Friday from a hospital in Temple, Tex., where he was taken following Thursday’s shooting rampage at Fort Hood’s Soldier Readiness Processing Center. The Army major, an American-born Muslim of Palestinian descent, is accused of opening fire Thursday with two handguns on soldiers preparing to deploy to the wars in Iraq and Afghanistan, killing 13 people and injuring 38 others before civilian police shot him four times.

“He is in stable condition, and he is conversing with the medical staff, the doctors and nurses who are assisting with his medical needs,” said Maria Gallegos, a spokeswoman at Brooke Army Medical Center about 150 miles southwest of Fort Hood.

She said she could not say whether Hasan has spoken to investigators about the Fort Hood shooting. She also declined to discuss Hasan’s injuries.

Another hospital spokesman said Hasan has been able to talk since he was taken off a ventilator Saturday.

Investigators from the Army’s Criminal Investigation Command and the FBI have been waiting to question Hasan as they try to establish a motive for the shooting and determine whether the suspect had any assistance or instigation from anyone else.

In a news conference Monday in front of III Corps headquarters, Lt. Gen. Robert W. Cone, Fort Hood’s commanding general, said, “I believe this was an isolated incident, a very unfortunate isolated incident.”

The investigators are looking into possible links between Hasan and Anwar al-Aulaqi, an American-born Muslim prayer leader who preached at the Dar al-Hijrah mosque in Falls Church, Va., when Hasan was attending it in 2001. U.S. authorities say Aulaqi, who left the United States in 2002 and settled in Yemen, has become a supporter and leading promoter of al-Qaeda.

In a blog posting Monday, Aulaqi called Hasan “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.” He praised “the virtue” of the Fort Hood shooting and said the only way a Muslim could justify serving in the U.S. Army was if he intended to “follow in the footsteps of men like Nidal.”

Cone declined to discuss the investigation Monday. But in response to a question, he told reporters that Hasan, who arrived at Fort Hood in July from Walter Reed Army Medical Center in Washington, was primarily involving in writing evaluations of patients.

“He didn’t have an extensive role in counseling soldiers,” Cone said.

Cone spoke as Fort Hood prepared for a memorial service Tuesday to honor those killed and wounded in the shooting, a service to be attended by President Obama, top military brass, members of the victims’ families and about 3,000 spectators.