Police in the U.S. are still trying to uncover the motive behind the murder of the most decorated sniper in the history of the U.S. military.
Chris Kyle, who wrote "American Sniper: The Autobiography of the Most Lethal Sniper in U.S. Military History," and his friend Chad Littlefield were shot dead at a firing range in Glen Rose, Texas on Saturday, allegedly by a man who Kyle was trying to help overcome psychological trauma stemming from the field of battle.
The man facing murder charges for the two deaths is Eddie Routh, 25, an Iraq war veteran who most likely accompanied the two men to the shooting range as part of a coping mechanism to deal with his trauma issues.
Kyle survived two shootings and six improvised explosive device attacks in Iraq, AFP reported. His military career ended three years ago upon his retirement, after which he started, among other things, a support group to help ex-soldiers cope with civilian life.
Many ex-soldiers must deal with some varying degree of post-traumatic stress disorder (PTSD), which is what Kyle's killer is believed to have suffered from. Kyle allegedly met Routh through his support group.
Tommy Bryant, Erath County Sheriff, said, "This shooter is possibly one of those people that he had taken out to the range, to mentor, to visit with, to help him."
"We lost two American heroes," Captain Jason Upshaw of the Erath County Sheriff's Office told AFP, noting that the likely murder weapon, a semi-automatic handgun, had been found at Routh's home.
Kyle, 38, was credited with more than 150 confirmed kills during a decorated decade-long service career that included four tours in Iraq.
A member of SEAL Team 3, Kyle provided protection for Marines and other US troops in combat zones. His longest and most remarkable kill was from 1.2 miles (two kilometers) away and took out an insurgent aiming a rocket launcher at an approaching Army convoy.
His memoir recounted battle experiences in the Iraqi rebel strongholds of Ramadi and Fallujah, and he wrote that Al-Qaeda terrorists dubbed him "The Devil," and said they had put a bounty on his head.
Kyle's death had earlier been confirmed by FITCO Cares, a support group he helped start which worked with returning soldiers who had PTSD.
"My heart is breaking," said FITCO's director, Travis Cox, noting that the former sniper leaves a wife and two children.
"Chris died doing what he filled his heart with passion -- serving soldiers struggling with the fight to overcome PTSD."
The US military confirmed on Sunday that Routh had seen active service with the Marines in Iraq, but that he was currently listed as a reserve.
The Dallas Morning News wrote that Kyle was awarded two Silver Stars and five Bronze Stars with Valor for his military service.
The fatal shooting comes amid a raging and bitterly fought debate in the United States over gun control, after several mass shootings in which publicly available high-powered, military-style weapons have been used.
The issue of gun killings at the hands of people suffering from mental or emotional illness has figured prominently in such arguments, with calls for tighter background checks for gun owners.