Alleged Fort Hood Shooter Bought Gun, Despite Ongoing Terrorism Investigation

WASHINGTON, Nov. 11, 2009— -- Sources tell ABC News that in August 2009, Maj. Nidal Malik Hasan walked into the Guns Galore gun store in Killeen, Texas, and legally purchased the FN Herstal tactical pistol that authorities believe was used to massacre soldiers at Fort Hood.

An FBI background check under the National Instant Background Check System was done when Hasan purchased the pistol -- but that information was never shared with the Joint Terrorism Task Force in Washington, which was aware that Hasan had repeatedly contacted a radical imam suspected of having ties to al Qaeda.

The FBI's Joint Terrorism Task Force ran down intelligence leads relating to Hasan late last year but closed the inquiry sometime in early 2009.

"The piece of information about the gun could have been critical," said former FBI Special Agent Brad Garrett. "One of the problems is that the law sometimes restricts you in what you can do."

As investigators continue to examine whether there were missed signals in the Fort Hood shooting massacre, some individuals are frustrated that there are still gaps in information-sharing, especially when it comes to looking at federal gun laws.

The Fort Hood shooting followed a June incident in Little Rock, Ark., where police say Abdulhakim Mujahid Muhammad opened fire at an Army recruiting station, killing a soldier. Muhammad was under FBI investigation for possible ties to terror and travel to Yemen.

A senior law enforcement official tells ABC News that Muhammad purchased a gun, in the weeks before the shooting, at a department store. An FBI background check was done -- but the FBI counterterrorism investigators working Muhammad's case were apparently unaware.