Unraveling a motive in trial of ‘American Sniper’s’ alleged killer

After eight days of testimony, the trial of the “American Sniper’s” alleged killer has not answered the one question that still haunts the families of Chris Kyle and Chad Littlefield.

Why Eddie Ray Routh allegedly killed the two men who were trying to help him remains a mystery.

There have been a series of confusing and incoherent explanations for Routh’s motives the afternoon of February 2, 2013.

We know Kyle sensed tension as he and Littlefield drove the former U.S. Marine to a gun range for an afternoon of bonding and helping Routh cope with what his family members believed was post-traumatic stress disorder.

Kyle secretly texted Littlefield, sitting next to him in a pickup, to say Routh was “straight up nuts.” Kyle’s wife, Taya, “could tell something was up” that afternoon when she spoke to her husband. Kyle sounded “irritated,” she has testified, then he never responded to a text asking if he was OK.

When Schmidle asked what triggered him picking up a firearm and shooting Kyle and Littlefield, Routh replied that he was angry that Littlefield would not participate in the shooting.

“I asked him a couple of times, ‘Hey, are you gonna shoot?’ ” Routh said. “This isn’t a spectator sport. It’s a shooting sport. You shoot. And that’s what got all, you know, wired up.”

After that exchange, Routh said, “I took care of business and then I got in the truck and left.”

Routh’s trial was postponed Monday due to weather, but it is scheduled to pick back up Tuesday. Closing arguments are expected this week.

CNN’s Jason Morris contributed to this report.

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