(Beaverton, OR)  --  Beaverton police are investigating after finding human remains in a fire pit at a woman's home yesterday.  Police say they were asked to check in on 57-year-old Katherine F. McDowell on Monday and when asked about her whereabouts, her 24-year-old son admitted to burning her body in the backyard fire pit.  Police checked the fire pit and believe the remains are McDowell's.  Matthew Gutierrez was arrested for abuse of a corpse.