STEPHENVILLE, Texas — The widow of the former Navy SEAL depicted in the blockbuster film “American Sniper” will be among the first to testify against the man charged with killing her husband.

A day before opening statements in the trial of former Marine Eddie Ray Routh, prosecutors said Tuesday that Chris Kyle’s widow, Taya, will take the stand. They also filed a document outlining “bad acts” allegedly committed by Routh that they may want to bring before the jury.

Defense attorneys have already said they will pursue an insanity defense for Routh, who family members say suffers from post-traumatic stress disorder.

Routh, 27, faces life in prison without parole if convicted of capital murder in the shooting deaths of Kyle and Kyle’s friend Chad Littlefield as the pair tried to help Routh at a shooting range two years ago.

A jury of 10 women and two men was seated Monday from an initial pool of 800 people, despite concerns from defense lawyers about finding an impartial jury because of pretrial publicity. The film based on Kyle’s memoir as a sniper who served four tours in Iraq has grossed nearly $300 million.

The intense attention on the case – largely because of Kyle’s memoir and the Oscar-nominated film – has also 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 that after the February 2013 shooting of Kyle and Littlefield, 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 has been in court since the jury screenings began last week, listening to the proceedings.

Another of the first witnesses prosecutors plan to call is Littlefield’s mother, Judy. District Judge Jason Cashon ruled that she and Taya Kyle can stay in court to watch proceedings after testifying.