Concluding he was on the "wrong side" in America's war, he told jurors at his court-martial that he switched sides.
So, victims and others are demanding, why is the November 2009 attack at Fort Hood being tried as a case of workplace violence and not as an act of terror?
Military law expert Scott L. Silliman says the answer is simple. Because the Uniform Code of Military Justice does not have a punitive article for "terrorism."
"They really didn't have an option," says Silliman, director emeritus of Duke University's Center on Law, Ethics and National Security in Durham, N.C. "He was an active-duty officer. The crime occurred on a military installation. ... It was obvious he was going to face a court-martial."
Victims of the shooting rampage filed a lawsuit last year over the administration's decision to treat the incident as workplace violence. They say that designation has robbed them of benefits and made them ineligible to receive the Purple Heart, awarded to service members wounded in battle.
On Monday, the staff of the magazine National Review launched a petition drive directed at Defense Secretary Chuck Hagel, arguing that the Army psychiatrist should be tried as an enemy combatant for what they consider "an Act of Terror."
"By not designating this event as such an act, it disrespects the lives of the 13 who lost their lives that day, and dozens more who were injured," the petition reads. "This is outrageous and I call on you to change the official designation now" before proceedings against Hasan go further.
While Silliman understands the outrage, he says transferring the case to civil courts -- where a terror charge could attach -- was just not possible.
"It would have been totally unprecedented to have that sort of thing occur," says Silliman, who has served as senior attorney at two large military installations and three major Air Force commands. "Now, if the crime had occurred off the post, then there might have been what we call concurrent jurisdiction between the civilian authorities and the military authorities."
Why can't the administration call this an act of terror without charging Hasan as a terrorist? According to a widely quoted Pentagon position paper opposing Purple Hearts for the victims that would allow the defense to argue that Hasan "cannot receive a fair trial because a branch of government has indirectly declared that Major Hasan is a terrorist -- that he is criminally culpable."
Reed Rubinstein, one of the attorneys representing a number of the shooting victims and their families, calls that argument "disingenuous."
The National Counterterrorism Center and State Department both counted the incident among terror attacks that year, he notes. The White House and Department of Defense have balked, he argues, because too many people didn't heed warning signs that Hasan was becoming increasingly radical leading up to his deployment to Afghanistan.
"The truth of the matter is, it comes down to politics," the Washington attorney says. "It comes down to covering up the political correctness that was the proximate cause of this attack in the first instance." Rubinstein is not calling for a terrorism charge but argues the government could administratively rule this was an act of terror so his clients can qualify for more benefits and the Purple Heart, which comes with its own set of recognitions and privileges.
Hasan is representing himself during the court-martial. Because he faces the death penalty, military law precluded him from entering a guilty plea. But he conceded in his opening statement Tuesday, as he has previously, that he did the shooting.
Military prosecutors could have added a civilian charge of terrorism, says Geoffrey Corn, a retired lieutenant colonel and former military lawyer. But he argues that would have added an unnecessary layer of complexity with little, if any, benefit.
"It's never been done in a military court before," says Corn, a professor at the South Texas College of Law. "Was he motivated by a terrorist agenda? Certainly. Will they present that evidence? Certainly. But the crimes he committed were premeditated murder and attempted premeditated murder."
Corn says it would be difficult to make the case for Hasan as an enemy combatant. While Hasan may have been inspired by al-Qaida and even had contact with known terror suspects, it does not appear he received orders from the group, Corn says.
Rubinstein terms the government's refusal to call the shooting incident a terrorist attack for purposes of awarding benefits "a kick in the teeth to the victims.
"They have to hear about workplace violence," he says. "They're told that what happened to them was no big deal. Pay no attention to the fact that he was a jihadist. Never mind that we knew and the FBI knew. But his career, because of his ethnicity and his religion, was more important to us than your lives. Forget all that."
Government attorneys have asked a federal judge to postpone the civil case, which seeks to reclassify the incident so as to make combat-related pay and other benefits available to the victims, until after the court-martial and post-trial processing are completed. That could take up to nine months.
Victim Shawn Manning estimates he has lost $2,000 a month in pay and benefits because of the decision to classify the injuries as resulting from workplace violence rather than combat or terrorist-related. Had his injuries been classified that way, the military would have paid the difference between his civilian and reserve salary, offered him better medical benefits and granted him greater disability payments.
"And Hasan is still collecting his major pay," growls Manning, who now works as a civilian mental health specialist at Fort Lewis, Wash.
"That's not correct," agrees former Staff Sgt. Alonzo Lunsford, who was shot seven times and still carries one slug in his back. He and Manning spoke to The Associated Press before a military judge's order this week not to discuss the case.
Silliman says that, too, is the way the military system operates.
"Remember, he is innocent until determined otherwise," he says. "He's going to be drawing full pay as a United States Army major ... until a sentence is awarded in the case and that sentence is approved by the convening authority."
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