Hasan is said to be in critical but stable condition, attached to a ventilator, while many of his victims are still fighting for their lives in hospitals. His comatose condition is frustrating attempts by investigators to work out the motive behind his killings.

"The military officer suspected in the shooting deaths of 13 people here was transferred from a civilian to a military hospital in part for security reasons," a military official said.
So far, the investigators are trying to unravel many unknowns about the man they say is responsible for the worst killing on a US military base, most of all his motive.

Though hampered by being unable to question him, investigators have seized his home computer during search of his apartment in Killeen in Texas and looked at his garbage to learn what motivated the suspect, who lay in coma shot four times by a gallant lady police officer in the frantic bloodletting.

Hospital sources said some of his wounds are extremely serious and he might not survive and this possibility is lending urgency to investigations.