By Jon Herskovitz
AUSTIN, Texas (Reuters) - Lawyers for the man convicted of murdering Chris Kyle, the former U.S. Navy SEAL whose best-selling autobiography was turned into the movie "American Sniper," have filed a notice of appeal with a Texas court, court officials said on Tuesday.
Eddie Ray Routh, 27, a former U.S. Marine, was found guilty on Feb. 24 of fatally shooting Kyle and Kyle's friend Chad Littlefield multiple times at a gun range about 70 miles (110 km) southwest of Fort Worth in February 2013.
Routh was sentenced to life in prison without the possibility of parole.
Prosecutors said he ambushed the two from the rear, waiting for Kyle to unload his weapon at the range before he attacked with a barrage of gunshots.
Defense lawyers, who tried unsuccessfully to have Routh declared innocent by reason of insanity, had sought to have the venue changed from Stephenville, a rural Texas city near where Kyle was raised and where many regard him as a hero.
Defense lawyers said Routh had been to hospitals at least four times because of his mental illness and was diagnosed as psychotic. They said he was suffering a paranoid episode when he went to the range and met the state's legal definition of insanity.
(Reporting by Jon Herskovitz; Editing by Peter Cooney)