US Army officials say the man who killed 13 people during a shooting spree at Fort Hood has been taken off a ventilator but still remains in intensive care.
Colonel John Rossi said he was not sure if Major Nidal Malik Hasan is able to communicate.
Hasan was shot during an exchange of gunfire during Thursday's attack. On Friday he was moved to Brooke Medical Centre in San Antonio, about 150 miles south-west of Fort Hood.
One of two police officers who confronted Hasan has been speaking about the incident which he says lasted less than a minute.
Sergeant Mark Todd joined Sergeant Kimberly Munley in the firefight. Sgt Todd was not wounded, but the exchange left his colleague injured.
Sgt Todd said that seconds after arriving at the scene, he saw a calm-looking Hasan, his gun drawn and his fingers pointing at people outside the Soldier Readiness Processing Centre. He then saw Hasan shooting at soldiers as they attempted to flee.
"He was firing at people as they were trying to run and hide," said the retired soldier who now works as a civilian police officer at the military base.
"I told him stop and drop your weapons, I identified myself as police and he turned and fired a couple of rounds at me. I didn't hear him say a word ... he just turned and fired."
There has been confusion about whose bullets actually brought Hasan down. At first, Sgt Munley's supervisor said it was her shot to Hasan's torso that stopped him, but Army officials would only say that an investigation was under way.
Sgt Todd said his female colleague was down by the time he engaged Hasan, but he wasn't sure if she had already wounded the suspect.
Sgt Todd said he fired his Beretta at Hasan, who fell on his back, then approached the suspect and saw he still had a weapon in his hand. The officer then kicked away the gun, which he said had a laser-aiming device attached to it.
Sgt Todd handcuffed Hasan and checked to see if he was still alive. "He had a good pulse," he said.
Sgt Munley has also won wide praise after the incident, and it's been revealed she "lost a lot of blood" from a gunshot wound to her left leg that had hit an artery.
Military authorities are continuing to refer to Hasan as a suspect in the shootings, and have not yet said if they plan to charge him in a military or civilian court.
His family has described a man incapable of the attack, calling him a devoted doctor and devout Muslim who showed no signs that he might lash out with violence.
"I've known my brother Nidal to be a peaceful, loving and compassionate person who has shown great interest in the medical field and in helping others," said his brother, Eyad Hasan.
"He has never committed an act of violence and was always known to be a good, law-abiding citizen."
But in the days since the incident a picture has emerged of a man who was forcefully opposed to the wars in Iraq and Afghanistan, was trying to get out of his pending deployment to a war zone and had struggled professionally in his work as an Army psychiatrist.