Defense to Present 3rd Day of Testimony in 'Sniper' Trial

Attorneys for the former Marine accused of fatally shooting "American Sniper" author Chris Kyle and another man are set to present a third day of testimony to support their insanity defense.

Eddie Ray Routh's attorneys have been calling friends and family members to testify to Routh's behavior before and after the February 2013 shootings of Kyle and Chad Littlefield at a shooting range in Texas.

Special: Clint Eastwood: You ’Must Read’ Chris Kyle’s Book — More

Prosecutors described Routh as troubled but said that any history of mental illnesses shouldn't absolve him of being accountable for the deaths.

The trial of the 27-year-old Routh has drawn intense interest, partly because of an Oscar-nominated film based on Kyle's memoir.

Special: American Sniper Gets 6 Oscar Nominations Including Best Picture. Get the Best-Selling Book That Started It All — Go Here Now.