Newport-area residents Mary Rosalee Gray, 60, and John Kingsley Pate, 70, are to be arraigned Thursday in Pend Oreille County Superior Court on charges they murdered Gray's husband and used a backhoe to bury his body. Deputy prosecutor Mike Carbone has charged Gray and Pate with first-degree murder and, as an alternative, second-degree murder. Charging documents say Robert Allen Gray, 70, was shot to death on or about May 21, but the documents give no motive.