The US soldier accused of slaughtering 16 Afghan civilians saw his friend's leg blown off the day before the rampage, his lawyer has said.
Mr Browne, 65, said that according to his client's family, he was standing next to another US soldier when the serviceman was horribly injured.
"We have been informed that at this small base that he was at, somebody was gravely injured the day before the alleged incident - gravely injured, and that affected all of the soldiers," he said.
Mr Browne offered no other details of the incident and it was no clear whether it prompted the horrific middle-of-the-night attack on Sunday. The soldier - who has not been named - had been injured twice during his three previous deployments to Iraq and he was loath to go to Afghanistan to begin with, the lawyer said.
Mr Browne declined to name the soldier amid concerns for his family, under protection on Joint Base Lewis-McChord, near Tacoma. He said the 38-year-old soldier had two children, aged three and four. The soldier, originally from the Midwest, deployed last December with the 3rd Stryker Brigade, and on February 1 was attached to a "village stability operation".
Mr Browne described him as highly decorated and said he had once been nominated for a Bronze Star. During tours in Iraq, the soldier suffered a concussive head injury in a car accident caused by a roadside bomb, Mr Browne said, and he suffered a battle-related injury that resulted in surgery to remove part of his foot.
He was screened by health officials after the head injury before he redeployed, Mr Browne said. He did not know if his client had been suffering from post-traumatic stress disorder, but said it could be an issue at trial if experts believe it was relevant.
The lawyer said he knew little of the facts of the shooting, but disputed reports that a combination of alcohol, stress and domestic issues caused the soldier to snap. He said the family was unaware of any drinking problem and described the couple's marriage as "fabulous".
The soldier is suspected of going on a shooting rampage in villages near his base, killing nine children and seven other civilians and then burning some of their bodies. The shooting, which followed a controversial Koran-burning incident involving US soldiers, has outraged Afghan officials. The suspect was flown out of Afghanistan on Wednesday evening to what officials describe as a pre-trial confinement facility in Kuwait.