WASHINGTON (Reuters) - If the U.S. soldier being held for the massacre of 16 Afghan civilians faces an Army court-martial, his lawyers will likely have a hard time persuading a military jury his shooting spree was the result of insanity brought on by trauma or stress.
The soldier, identified by a U.S. official as Army Staff Sergeant Robert Bales, was treated for a traumatic brain injury he suffered in a vehicle rollover in 2010 while deployed in Iraq, one of three tours he served there, officials have said.
A lawyer hired for Bales has already raised health as a possible defense, including post-traumatic stress disorder (PTSD). "It is commonly used in military defense," attorney John Browne told Reuters on Friday.
Defense lawyers have not been successful in military courts arguing that a traumatic brain injury or post-traumatic stress disorder made soldiers legally insane at the time of a crime, a U.S. military judge advocate told reporters this week.
Hundreds of cases have been prosecuted in the military courts for crimes by U.S. soldiers in Iraq and Afghanistan ranging from misdemeanors to felonies including murder, though precise statistics for all military branches were not available.
The Army is investigating the killings, the first step in a lengthy military legal process. It could take weeks to draft charges and longer to determine whether the case should be referred for a court-martial.
Bales was flown to Fort Leavenworth, Kansas, where he will be held pending the investigation.
While no charges have been brought yet, he would face life in prison at a minimum if convicted of murder at a court-martial although there is an option for parole. Bales could have to fight the death penalty, however that is rare in the military.
Courts-martial are similar to traditional criminal trials: they allow for a mental evaluation and an insanity defense, which in the military is known as "not guilty but only by reason of lack of mental responsibility." The threshold is high.
The military judge advocate who briefed reporters said defense lawyers had yet to successfully argue that a soldier was insane because of traumatic brain injury or post-traumatic stress disorder.
Typically, before charges are brought, military lawyers or the defense team can request that a "sanity board" determine whether the soldier can assist in his own defense and understands the nature of his actions.
"Insanity from a legal standpoint requires a significant mental disease or defect so that the person could not appreciate the nature, quality or wrongfulness of their behavior," the military judge advocate said.
One legal expert said the defense team could enlist psychiatrists and other mental health experts to build the case that the person was so mentally disabled he did not know what he was doing at the time of the alleged crimes.
"I don't think anyone is going to be able to get off with an ordinary post-traumatic stress disorder" defense, said Jenny Martinez, a Stanford Law School professor. "You have to show a real incapacity to understand what's going on."
Defense Secretary Leon Panetta told reporters this week the death penalty could be sought in the Afghanistan massacre case. Browne said it was still on the table.
Such a sentence is extremely rare. The last execution in a U.S. military case dates back to 1961 and only a handful are on death row now.
Charges brought against U.S. Army Major Nidal Hasan, who is accused of killing 13 and injuring 32 others during a 2009 shooting spree at Fort Hood in Texas, included a recommendation that the death penalty be sought.
In a case in which military prosecutors are seeking the death penalty, a defendant cannot plead guilty. For a conviction in such cases, a military jury must come to a unanimous decision in deciding both guilt and whether to impose the death penalty.
The Pentagon did not immediately respond to a request for details about criteria for when the death penalty can be sought.
There are other requirements. A jury can only impose a death sentence if there was an aggravating factor to the crime, such as premeditation, and any mitigating circumstances are outweighed by the aggravating factor.
Alcohol use could be considered as either an aggravating or mitigating factor, according to military rules.
Lawyers who have defended soldiers in courts-martial said there would be intense pressure to pursue a death sentence in the face of outrage from Afghan officials.
"I think the political pressure is going to be such that they would still refer it with the full authority of the death penalty," said Neal Puckett, a military defense lawyer who helped represent Marines accused in the 2005 murder of 24 civilians in the Iraqi city of Haditha.
The military justice system requires a U.S. president to approve the execution of a service member and the last approval came in 2008 for a soldier convicted of multiple murders and rapes. The soldier remains on death row.
The last execution was of Army Private John Bennett, who was hanged in 1961 after being convicted of rape and attempted murder of a young girl. A Los Angeles Times article in 2000 said Bennett had a history of mental illness but it was not raised during his brief trial and his appeals failed.
Since the current death penalty system was adopted by the military in 1984, there have been 52 court-martial cases in which the death penalty was sought but only 16 received such a sentence. Six are awaiting execution, two had sentences commuted to life in prison and eight were set aside on appeal, said Dwight Sullivan, a U.S. Air Force defense lawyer.
Haytham Faraj, another defense lawyer in the Haditha case, said: "The defense strategy is probably going to be ‘yes he did it, but look at these factors that impacted his state of mind' and the goal here would be to avoid the death penalty."
Military juries typically are made up of officers though the defense could request the inclusion of enlisted service members.
The massacre of civilians in Afghanistan has led to wide-ranging comparisons to other incidents in which civilians were killed either in random attacks or were targeted by American service members.
Legal experts said the case may bear a closer resemblance to the 2009 Fort Hood shooting, which involved a single soldier who started shooting indiscriminately. Defense lawyers in that case have yet to say whether he will enter an insanity plea.
There have also been comparisons to the Haditha attack in 2005, in which military prosecutors believed a group of Marines launched attacks as retribution for a roadside bomb that killed a member of their unit.
Charges were dismissed for six of the eight Marines accused of that attack, one was cleared of criminal wrongdoing and the leader of the group pleaded guilty to a lesser charge of being lax in his orders to his unit and he avoided jail time.
The shooting has also been compared to the 1968 My Lai massacre in Vietnam in which an Army unit killed hundreds of civilians. It too was found to have been revenge for attacks on U.S. soldiers and deemed poor leadership by commanders.
The officer who helped lead the My Lai attack, Lt. William Calley, was court-martialed and sentenced to life in prison for premeditated murder in 1971. He served three years under house arrest before being released by a federal judge.
Long sentences have been handed out for other civilian killings, including an attack in which a group of U.S. soldiers gang-raped and murdered a 14-year-old Iraqi girl before burning her body. They also killed her family.
Private Jesse Spielman was found guilty at a court-martial of four counts of murder and was sentenced to 110 years in prison. Two others were sentenced to 90 and 100 years in prison for what was seen as a random killing south of Baghdad in 2006.
Those cases and other similar incidents have raised another possible defense for the soldier in the present case: Was there a failure at the command level by officers to instill discipline among the soldiers and ensure non-combatants were not targeted?
Lawyers who suggested that defense also noted it could be a stretch because the Army sergeant appeared to act alone.
"You consider everything when you're defending a guy like this and you don't lightly discard any avenue," Puckett said. But he voiced doubts, adding, "This guy walked off the forward operating base which you can't just do."
Additional reporting by David Alexander in Washington and Laura Myers in Seattle; editing by Todd Eastham