(Portland, OR)  --  The mother of a 17-year-old who was shot to death by a Portland police officer is calling for a federal investigation.  A Multnomah County grand jury cleared Officer Andrew Hearst of any criminal wrongdoing in the shooting of Quanice Hayes, following a robbery at a motel on Northeast 82nd Avenue on February 9th.  Authorities say Hearst shot Hayes during a confrontation during which Hayes made "repeated and deliberate motions with his hands to the area of his waistband and pockets."  Hayes's mother, Venus Hayes, claims her son was on his knees when he was shot and didn't have a replica handgun as reported by the Portland Police Bureau.