Maj. Nidal Malik Hasan , the alleged Fort Hood gunman and a psychiatrist who worked in a hospital at the base , is blamed for the deaths of 12 soldiers and one Army civilian employee , and for wounding at least 38 others . If convicted , Hasan will join an infamous list of Americans who have committed acts of mass murder . Since 2005 , there have been at least 11 other incidents where gunmen have opened fire on groups of victims .
Since 2001 , Hasan had been unable to leave the military , a family spokeswoman said . The Associated Press contributed to this report. The police officer who shot Hasan , ending the massacre , was among the wounded .