A Texas jury last night convicted Marine veteran Eddie Ray Routh in the killings of "American Sniper" author Chris Kyle and his friend Chad Littlefield at a gun range in 2013.

Shortly after Routh was sentenced to life in prison, Kyle's friend and former Navy SEAL Marcus Luttrell posted the following to Facebook.

 

Luttrell appeared on "The Kelly File" tonight for an exclusive interview with Martha MacCallum.

"It was a relief, a vindication for the Kyle and Littlefield families," Luttrell said, adding that he didn't buy Routh's defense of insanity due to PTSD.

"First of all, having PTSD is not a straight line to commit murder. It not a straight line to doing anything [that's] breaking the law," Luttrell said.

"Everybody has stress in their life. Everybody has a hard day. Yeah, do we have some more than others when we're overseas? Absolutely." Luttrell said. "Bottom line is [Routh] was an angry drunk. And that's what came out."

"He'd get drunk, he'd get high. He'd go do something bad, the cops would show up. He's say he was a veteran, he had PTSD. [They'd] throw him in the mental hospital. Couple days, he'd be out, go straight back doing to dope, getting drunk, getting angry. And he wore that out. And that's what the DA pointed out."

"The jury came back and their verdict was absolute."

Watch the exclusive interview above.