Police said Barnes, 24, appears to have died from exposure to the elements after he trudged into chest-deep snow in the park to elude SWAT teams, the Associated Press reports. He was found facedown in an icy creek, wearing only a T-shirt, jeans and one sneaker, according to police.
Authorities said they found a knife, two guns and ammunition near his body.
Barnes, an Iraq War veteran, allegedly fled to the park early Sunday morning, after he was involved in a shooting at a New Year's Eve party nearby that wounded four people. Police say he blew through a tire-chain checkpoint at the park and murdered park ranger Margaret Anderson, 34, shooting her at a second roadblock before she even had a chance to exit her vehicle.
The park was closed on Sunday afternoon while authorities launched a manhunt for Barnes and remained closed Tuesday as the investigation continued.
Rangers in Shock"We have never had an incident like that at Mount Rainier National Park," park spokesman Kevin Bacher said Monday, according to the Seattle Times.
"Our rangers are very much in shock," he added. "We ... absolutely take it personally. Everybody knew Margaret. Everybody was friends with Margaret. She didn't have an enemy in the world."
Barnes's military service ended in 2009, when he was charged with DUI and improperly transporting privately-owned weapons, the Times reports. He subsequently received a misconduct discharge from the Army, where he had been a private first class.
Nicole Santos, Barnes's former girlfriend and the mother of his young daughter, told police last summer, when the couple were going through a custody dispute, that she believed he was suicidal and may be suffering from post-traumatic stress disorder, according to the AP. She also said he kept an "arsenal of weapons" at his home.
Anderson's husband, Eric, is also a ranger and was working elsewhere in the park when she was killed. They have two daughters, ages 3 and 1.