First responders prepare the wounded for transport in waiting ambulances outside Fort Hood's Soldier Readiness Processing Center, after a mass shooting at the military base November 5, 2009. Investigators searched for the motive on Friday behind the mass shooting at the sprawling U.S. Army base in Texas, in which an Army psychiatrist trained to treat war wounded is suspected of killing 13 people. The suspected gunman, Major Nidal Malik Hasan, a Muslim born in the United States of immigrant parents, was shot four times by police, a base spokesman said. He was unconscious but in stable condition. Photo taken November 5, 2009.