Days after the shooting, reports in the media revealed that a Joint Terrorism Task Force had been aware of e-mail communications between Hasan and the Yemen-based cleric Anwar al-Awlaki, who had been monitored by the NSA as a security threat, and that Hasan's colleagues had been aware of his increasing radicalization for several years. The failure to prevent the shootings led the Defense Department and the FBI to commission investigations, and Congress also held hearings...
At approximately 1:34 p.m. local time, Hasan entered his workplace, the Soldier Readiness Processing Center, where personnel receive routine medical treatment immediately prior to and on return from deployment. He was armed with the FN Five-seven pistol, which he had fitted with two Lasermax laser sights: one red, and one green. A Smith & Wesson .357 Magnum revolver (an older model) was later found on Hasan's person, but he did not use it to shoot any of the victims.
According to eyewitnesses, Hasan had taken a seat at an empty table and bowed his head for several seconds when he suddenly stood up, shouted "Allahu Akbar!" and opened fire. Witnesses said Hasan initially "sprayed bullets at soldiers in a fanlike motion" before taking aim at individual soldiers. Eyewitness Sgt. Michael Davis said: "The rate of fire was pretty much constant shooting. When I initially heard it, it sounded like an M16."
