US Army soldiers comfort each other at the Fallen Soldier Memorial at Fort Hood on November 10, 2009 during a ceremony honoring the 13 soldiers and civilians killed in a shooting rampage at the army base on November 5. US Army Major Nidal Malik Hasan, 39, a psychiatrist and specialist in combat stress, who allegedly killed 13 people and wounded 42 in a shooting rampage, is believed to have acted alone by investigators and no motive has been established.