. >> reporter: he asked his best friend chad littlefield to come with him and rout to the range southwest of dallas. >> chris was in the front and chad was behind. >> reporter: rout waits until chris has fired his shots down range and guns down chad. then before chris knows what's happening, routh shoots him six times all in the back. >> i know they didn't either one of them saw it coming. >> reporter: routh takes his gun and truck and heads to hi sister's house telling her he just killed two men. the second he leaves she called 911. >> my brother said he commit a murder. >> reporter: meanwhile, taya was at home with her children. how were you able to tell your children about what happened to chris? >> it was one of the hardest things i ever had to do. i told them something really bad happened and daddy got hurt and my daughter looked at me and she said, is he dead and then i just shook my head. >> reporter: police tracked down chris' truck within hours. he is arrested and charged with the first-degree murder of chris kyle and chad littlefield. in the dusty west texas town of stephenville

. >> that brisk february morning, chris asked his best friend, chad littlefield to come with him and ph to come to the rough creek lodge gun range, a hunting resort about two hours southwest of dallas. but when chris and chad pick up ralph a chris's big black truck around 1:00 in the afternoon, ralph is weary and the feeling is mutual. the strange man in the back seat set off alarm bells for chad and chris. while driving chris text chad, this dude is straight up nuts. chad responds, he's right behind me. watch my 6. military slang for watch my back. still, when they arrive at the range, chris goes ahead with the day's plan. >> chris was definitely in the front and chad was behind. and i know that he had old wet kind of replica guns and both were empty. ralph waits until chris has fired all his shots down range and guns down chad. then before chris knows what's happening, ralph shoots him six times all in the back. >> i know that chad and chris both had their side arms holstered and on safety. the shooter, i think, was over there. and he definitely had some loaded weapons that turned o