The American Nidal Hasan , the US Army major and psychiatrist charged in the 2009 Fort Hood shooting , had come to the attention of colleagues and superiors years before the shootings ; they documented their concerns about his mental state . The Department of Defense has classified the event as " workplace violence " rather than terrorism , pending Hasan 's court martial . Some observers believe that his personal characteristics are more like those of other mass murderers than terrorists ; he did not belong to any group
2009 Fort Hood shooting
2009 Fort Hood shooting
Domestic terrorism