Eddie Ray Routh has confessed to the February 2013 slayings but has pleaded not guilty by reason of insanity.
Defense attorneys say Routh was insane when Kyle and Chad Littlefield took him to a shooting range to provide support and camaraderie. Prosecutors say he knew his actions were wrong and should be convicted of capital murder. They aren't seeking the death penalty.
In a video confession shown to jurors Monday, 27-year-old Routh told Texas Ranger Danny Briley that he shot Kyle first and added, "I'm just sorry for what I've done."
Briley testified Monday that Routh said he knew his actions were wrong.
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