'American Sniper': Latest Images of Chris Kyle's Alleged Killer Released

Eddie Ray Routh is charged with killing Chris Kyle and Chad Littlefield.

Eddie Ray Routh was pictured clean-shaven with a buzz cut -- a marked difference from the scruffy beard he had when he was arrested in February 2013.

Rather than appearing in the striped prison jumpsuit that he was seen in last year or the orange jumpsuit he was wearing when his mugshot was taken on the day of his arrest, Routh was wearing an olive-colored collared shirt, a grey blazer and glasses.

Routh was also noticeably larger than he was at the time of his arrest.

Today marks the start of an important day for the 25-year-old as opening statements in his murder case are scheduled to begin on Wednesday.

Up until now, little has been known about Routh.

He was arrested on February 2, 2013 after his sister called police to report that her brother had allegedly admitted to killing two people at a gun range.

He has since been charged with the deaths of Chris Kyle and Kyle's friend Chad Littlefield, who had gone with Routh to a local gun range as part of work Kyle did with veterans.

According to The Associated Press, Routh's attorneys are expected to mount an insanity defense, using Routh's tour in Iraq and his participation in a relief mission to Haiti after the earthquake as contributing factors in his diagnosis. The prosecution has already made it clear that they do not plan to seek the death penalty in this case.

The film "American Sniper," which details Kyle's four tours in Iraq, has broken box office records and has been nominated for an Oscar for Best Picture.