A forensic psychologist said the ex-Marine who shot "American Sniper" author Chris Kyle and another man wasn't legally insane, but had a personality disorder made worse by the use of marijuana and alcohol.
Prosecutors on Friday called a rebuttal witness in the trial of Eddie Ray Routh, who's charged with killing Kyle and his friend Chad Littlefield at a gun range in 2013. Routh's attorneys, who are pursuing an insanity defense, rested their case Thursday.
Dr. Randall Price testified Friday that he thought Routh "did know what he was doing was wrong, and he did it anyway."
Price believes Routh has a personality disorder which makes him distrustful. His paranoia on the day of the murders was induced by his marijuana and alcohol abuse.
Delusions about Kyle and Littlefield being hybrid pig assassins could have come from a Seinfeld episode or the Boss Hog TV show.
And on the day of the murders Routh was upset because the Department of Veterans Affairs wouldn't give him education benefits, a home loan or pay for any post-traumatic stress disorder treatment until he got sober, Price said.
Routh told Price "I shot them. I thought, ‘What have I done?' And I was immediately remorseful," the psychologist testified.
Price said Routh's mental health improved just a few days after his arrest, likely because he no longer has access to alcohol and drugs.
The 27-year-old defendant faces life in prison without parole if convicted.
The Oscar-nominated film based on Kyle's memoir has spurred intense interest in the case.
The Associated Press contributed to this report.