Lawyer: 'American Sniper' said ex-Marine 'straight-up nuts'

STEPHENVILLE, Texas -- Shortly before he was shot to death by a troubled former Marine at a Texas gun range, legendary Navy SEAL sniper Chris Kyle texted a buddy, "This dude is straight-up nuts," a defense attorney told jurors Wednesday.

A lawyer for Eddie Ray Routh said in opening statements of the man's murder trial that Routh's insanity was so evident, Kyle and his friend Chad Littlefield exchanged texts expressing alarm as the three rode together in February 2013 to a Texas shooting range.

"He's [sitting] right behind me, watch my six," Littlefield texted back, using a military reference for watching one's back.

But a prosecutor said even with a history of mental illness, Routh still knew right from wrong.

The case has drawn intense interest, largely because of Kyle's memoir about being a sniper who served four tours in Iraq. The Oscar-nominated film based on the book has grossed nearly $300 million.

Erath County District Attorney Alan Nash described the 27-year-old Routh as "a troubled young man" who on the morning of the killings numbed himself with marijuana and whiskey. He said a history of mental illness should not absolve Routh of being accountable for the deaths.

"The evidence will show that mental illnesses, even the ones that this defendant may or may not have, don't deprive people from being good citizens, to know right from wrong," Nash said.

Tim Moore, an attorney for Routh, said Kyle and Littlefield's text exchange shows how Routh was spiraling out of control. He told jurors that Routh was suffering from severe mental strain that day and thought he needed to kill the two or they would turn on him.

"He thought he had to take their lives or he was in danger," Moore said.

Kyle's widow, Taya Kyle, testified Littlefield and her husband were close, and enjoyed spending time with veterans as a way to help them ease back into civilian life. She detailed her husband's struggles after leaving the battlefield, saying he had post-traumatic stress disorder, was irritable and slowed by physical ailments.

She said her husband had been approached by Routh's mother to help her son.

The intense attention on the case has brought renewed focus to the mental struggles former military members face.

Routh was a small-arms technician who served in Iraq and was deployed to earthquake-ravaged Haiti before leaving the Marines in 2010. Authorities say after the February 2013 shooting, Routh drove to his sister's house in Kyle's truck, admitted to the killings and told his sister "people were sucking his soul."

Routh faces life in prison without parole if convicted.