District Attorney Alan Nash said Chad Littlefield and Chris Kyle were "best friends" with a shared passion of helping veterans.

Eddie Routh was described as an average student who graduated from high school in 2006 and wanted to follow in his father's footsteps by joining the United States Marines.

In 2010 Routh was assigned to a rescue mission following an earthquake in Haiti. He was honorably discharged in 2010.

After returning from Haiti, Routh became so troubled he thought he had a tape worm inside of him.

On Feb. 1, 2013, the night before the murders, Eddie Routh proposed to his girlfriend.

On the morning of Feb. 2, 2013, Routh admitted to smoking marijuana laced with formaldehyde and drinking whiskey.

As Kyle, Littlefield and Routh made their way to Rough Creek Lodge on Feb. 2, 2013, Routh rode in the backseat of Kyle's truck.

On the way to Rough Creek, Kyle sent Littlefield, who was sitting right beside him, a text message that said, "This dude is straight up nuts." Littlefield replied, "He's right behind me, watch my six."

Kyle was shot five times in the back and side and once in the head. Littlefield suffered seven gunshot wounds - four in the back, one in the hand, one in the face and one in the head. Two different guns were used.

After shooting and killing Kyle and Littlefield, Routh reloads Kyle's 9 mm with a new clip, then flees in Kyle's truck.

After the murders and before his arrest, Routh stopped at Taco Bell for a burrito.

In an interview with a Texas Ranger after his arrest, Routh confessed to the crime.