(CNN) -- A U.S. soldier accused of killing 16 Afghan villagers in a shooting rampage could face the death penalty if he is found guilty in a court-martial.
The military has referred the case of Staff Sgt. Robert Bales to a court-martial authorized to consider capital punishment, according to a military statement released Wednesday.
Another six Afghans were wounded in the spree near a small U.S. base in Afghanistan's Kandahar province last March, the military said.
"The charges are merely accusations, and the accused is presumed innocent until proven guilty," the military emphasized in its statement.
Bales' defense attorney John Henry Browne said Wednesday he didn't receive any notice from the Army or the prosecutors about the decision to pursue the death penalty; he said he found out about it through the media.
"That's how much we seem to matter to the prosecutors and the general," quipped Browne.
"I am concerned this is a death penalty case, but I am not surprised. We've prepared him for this. He knows he's being singled out," Browne said.
"We understand that decision, but we think it's totally irresponsible of the government and the Army," Bales' lawyer said.
"We think the Army is attempting to escape responsibility for the decision to send Sgt. Bales to Afghanistan for his fourth deployment, knowing that he had (post-traumatic stress disorder) and a concussive head injury," Browne said. "I think that the person who made the decision to send Sgt. Bales to the most dangerous area in Afghanistan in a small outpost is responsible for Sgt. Bales being in Afghanistan, and he should have never been there."
Bales' wife, Karilyn, has called the accusations "completely out of character of the man I know and admire."
In a statement released Wednesday, she wrote, "I no longer know if a fair trial for Bob is possible, but it very much is my hope and I will have faith."
She and their children visit Bales every weekend, and "for a few hours I can see and feel the love that flows" between them, she added.
Afghan authorities have pushed for swift action.
"He committed a mass killing crime, and we would like the court in the United States to implement justice and punish him according to the crime," Ahmad Zia Syamak, a spokesman for Afghan President Hamid Karzai, told CNN last month.
But Browne said prosecutors may regret hastily moving the case forward.
"The reality is almost every death case in the Army -- almost every -- has been overturned on appeal, and there hasn't been an execution in the Army since the early '60s," Browne said, referencing the 1961 hanging of Pvt. John Bennett.
CNN's Josh Levs and Paul Vercammen contributed to this report