Texas man arrested for death of 13-year-old girl found dead in 2010 By FOX 7 Austin Digital Team Published article According to police, the eighth-grader was last seen on Dec. 27, 2010, in Mitchell County. Her mother reported her missing the next day. BIG SPRING, Texas - A 35-year-old Texas man has been arrested for the murder of a 13-year-old girl in 2010. Shawn Casey Adkins was arrested Monday, June 14, in Big Spring and charged with one count of murder in the death of 13-year-old Hailey Dunn. According to police, the eighth-grader was last seen on Dec. 27, 2010, in Mitchell County. Her mother reported her missing the next day. Despite a search, there was no sign of Dunn until March 16, 2013, when her remains were found near Lake JB Thomas in Scurry County.