A former US Marine Goes on Trial in Texas Today Charged With Killing The Real Life American Sniper.

Ex-Marine corporal Eddie Ray Routh goes on trial in Texas charged over the death of Navy SEAL Chris Kyle in February 2013.

Navy SEAL Chris Kyle, credited as the most deadly sniper in US military history, was shot dead at a gun range in February 2013.

His friend Chad Littlefield was also shot dead during the attack.

The two men had taken former Marine corporal Eddie Ray Routh to the range as part of his treatment for post-traumatic stress disorder (PTSD).

Routh does not deny shooting the men, but is expected to plead not guilty to murder by reason of insanity.

The movie adaptation of Kyle's autobiography American Sniper is now the highest-grossing war movie of all time.

Both the film and Bradley Cooper, who plays Kyle, have been nominated for Oscars.

The movie has attracted controversy with claims it glorifies violence in its telling of Kyle's 160 confirmed "kills" during four tours in Iraq.

But in Kyle's home town of Midlothian, where his widow Taya and two children still live, they dismiss the criticism.

Dennis DeWeerde, who runs the barbecue restaurant where Kyle regularly ate Sunday lunch, told Sky News: "Chris truly was a hero and you could sit and talk to him about things that happened overseas and he really was genuine in saying he was more worried about the people he didn't save.

Eddie Ray Routh is expected to plead not guilty to murder

"I don't know how else to describe him but for what he was, a true American hero."

The trial will take place in the small town of Stephenville.

Until now the town was most famous for being the "Cowboy Capital of the World".

Stephenville has been swamped by media from around the world who are covering the trial.

The jury has been told to ignore the film - currently playing at the town's cinema, four miles from the court - and focus on the evidence.

Several potential jurors were released after saying they had already made up their minds.

Routh's lawyers had asked for a delay in proceedings, or for the trial to be moved, because of the attention surrounding the movie.

And military veterans' organisations have questioned their use of PTSD as his defence.

Cliff Sosamon, president of the North Texas Military Association, said: "Just because you have post-traumatic stress, it doesn't give you the right or the excuse to do those kind of things.

"If that was the case you'd have veterans running wild all over the place, and that's not the case at all."

The trial is expected to last two weeks.

Prosecutors have decided not to seek the death penalty so, if found guilty, Routh would face life in prison.

If he is found not guilty by reason of insanity, he would most likely be sent to a psychiatric hospital.