Autistic boy believed foundGARLAND (AP) — The Dallas County Medical Examiner's Of* fice was examining a partially decomposed body to determine if it is that of an autistic boy who has been missing since July 18.Two Mesquite residents found the body in a field in Mesquite, a suburb east of Dallas, about 6:10 p.m. Thursday. The area is about 10 miles from where 8-year-old Kim Nguyen vanished from his parents' Garland home, Officer Larry Rollins said.Garland police believe the body is the child’s. They hope to release autopsy results at a press conference scheduled for today, Rollins said.Kim was last seen early July 18, when he wrestled playfully with his older brother Michael until he was told to w ateh television. He was gone when his father checked on him about 7 a.m.