Former Navy SEAL Chris Kyle and his neighbor Chad Littlefield took former Marine Eddie Ray Routh to a Texas gun range to help him, but for some reason Routh allegedly turned his gun on his two mentors, killing them both, police said today.

ABC News affiliate WFAA-TV in Dallas reported that investigators said Routh, 25, was recovering from post traumatic stress disorder, but police today said they could not confirm that.

Routh, a corporal in the Marines from June 2006 to January 2010, was deployed to Iraq in 2007 and Haiti in 2010, according to the Pentagon. His current duty status is listed as reserve.

"Apparently Mr. Kyle works with people that are suffering from some issues that have been in the military and this shooter is possibly one of those people, that he had taken out to the range to mentor, to visit with, to help him, you know, that's all I can tell you," said Erath County Sheriff Tommy Bryant.

"Kind of have an idea that maybe that's why they were at the range, for some type of therapy that Mr. Kyle assists people with, and I don't know if it's called shooting therapy," Bryant said. "I don't have any idea but that's what little bit of information that we can gather so far."

Witnesses told police that Routh left the shooting scene in Kyle's pickup truck. He drove to his sister's home in Midlothian and when he allegedly told her and her husband that he had shot the two men, the couple called police.

When investigators got there, Routh fled in another vehicle, but he was captured a short time later.

Routh was charged with two counts of capital murder and was being held today at the Erath County Jail on $3 million bond.  Read more at ABC News