Major Nidal Malik Hasan, the U.S. Army doctor identified by authorities as the suspect in a mass shooting at the U.S. Army post in Fort Hood, Texas, is seen in this undated handout photo from a pdf file of the U.S. Government Uniformed Services University of the Health Sciences downloaded on November 6, 2009. Investigators searched for the motive on Friday behind the mass shooting at a sprawling U.S. Army base in Texas, in which the Army psychiatrist trained to treat war wounded is suspected of killing 13 people. 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. REUTERS/Uniformed Services University of the Health Sciences/Handout (UNITED STATES MILITARY CRIME LAW HEADSHOT CONFLICT IMAGES OF THE DAY) QUALITY FROM SOURCE. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS