FN 57 Pistol 5.7 MM!

Maj Nidal Malik Hasan used a FN 57 pistol (aka the Five-Seven by FN Herstal), a 5.7 MM pistol. The FN 5.7 is a 5.7 millimeter pistol at issue in the Foot Hood shooting.
The FN57 allegedly comes in a version that goes through armor; that version is reportedly only sold to law enforcement and military customers. Other reports say rather a change in the version of ammunition, not of the actual 5.7 mmSo how did Major Nidal Malik Hasan get an FN5.7 before his attack at Fort Hood? The Five Seven was the subject of a U.S. federal ban in 2005 that failed.
Tonight revelation that Hasan bought the FN 5.7 at at store in Kileen, Texas months ago. AP is reporting tonight “the most powerful type of ammunition for the FN 5.7 … is available only to law enforcement and military personnel… It is not clear wheat kind of ammunition” that Hasan bought.
The store has not commented. Budd Hallberg tells Statesman.com tonight “It’s …to be used in combat … What in the h-ll would a doctor have it for?”