WASHINGTON - NOVEMBER 06:  An exterior view is seen at the Walter Reed Army Medical Center November 6, 2009 in Washington, D.C. Major Nidal Malik Hasan worked at the center for six years. Transfered to Texas in July, Hasan killed 13 people and injured 31 more in a shooting rampage at Ft. Hood, Texas, yesterday. Getty Images logo Getty Images 2 weeks ago

WASHINGTON - NOVEMBER 06: An exterior view is seen at the Walter Reed Army Medical Center November 6, 2009 in Washington, D.C. Major Nidal Malik Hasan worked at the center for six years. Transfered to Texas in July, Hasan killed 13 people and injured 31 more in a shooting rampage at Ft. Hood, Texas, yesterday.