Forensics expert Howard Ryan testifies during the capital murder trial of former Marine Cpl. Eddie Ray Routh in Stephenville, Texas February 24, 2015. A Texas jury could begin deliberations as early as Tuesday in the trial of Routh, who is charged with murdering Chris Kyle, the former U.S. Navy SEAL whose autobiography was turned into the blockbuster movie "American Sniper" and Kyle's friend Chad Littlefield in 2013. REUTERS/Michael Ainsworth/Pool (UNITED STATES - Tags: CRIME LAW MILITARY)