Eddie Ray Routh, 25, was indicted by an Erath County grand jury on Wednesday for allegedly murdering "American Sniper" author Chris Kyle and his friend Chad Littlefield.
Rough was indicted for capital murder for allegedly killing the two at a gun range on Feb. 2.
Authorities say Kyle, Littlefield and Routh arrived together at the Rough Creek Lodge shooting range, about 50 miles southwest of Fort Worth, on the afternoon of Feb. 2. Routh later fled in Kyle's truck.
According to a search warrant, Routh told his sister and brother-in-law that the men "were out shooting target practice and he couldn't trust them so he killed them before they could kill him."
Routh's brother-in-law later told authorities that Routh had recently been diagnosed with PTSD.
Routh has been on suicide watch since his arrest. There is no date set for his trial.