By Jonathan Kaminsky
TACOMA, Washington (Reuters) - Lawyers for a U.S. soldier who pleaded guilty in June to the slaughter of 16 Afghan civilians are expected to seek the dismissal of the prosecution team at a hearing on Tuesday, claiming that the fairness of the soldier's upcoming sentencing proceeding is at risk.
Military prosecutors were mistakenly provided an unredacted copy of a court-ordered mental health evaluation of Army Staff Sergeant Robert Bales, which civilian defense lawyer John Henry Browne has said would give them an undue advantage in the sentencing phase of the case.
The motion seeking to remove the prosecutors is among those filed by Bales' lawyers to be considered at Tuesday's pre-sentencing hearing, an army spokesman said. It comes less than a week before a sentencing proceeding set to decide if Bales will ever have a chance at parole.
Bales, 40, pleaded guilty in June to walking off his base in Afghanistan's Kandahar province before dawn on March 11, 2012, and gunning down civilians in their homes in at least two villages.
Bales, a decorated veteran of four combat tours in Iraq and Afghanistan, faces life in prison under a deal that spared him the death penalty. A military jury is still to determine whether he will ever be eligible for parole.
The attack marked the worst case of civilian slaughter blamed on a lone, rogue U.S. soldier since the Vietnam War, and further strained U.S.-Afghan relations after more than a decade of conflict in that country.
Upon pleading guilty in June, Bales acknowledged the killings and told the court there was "not a good reason in this world" for his actions.
Defense attorneys have argued that Bales, a father of two from Lake Tapps, Washington, was suffering from post-traumatic stress disorder and a brain injury even before his deployment to Afghanistan.
(Editing by Cynthia Johnston and Leslie Adler)