(Salem, OR)  --  A Salem man is facing charges, after being accused of abducting his 87-year-old grandmother at knifepoint.  The Marion County Sheriff's Office says 22-year-old Robert White is believed to have been under the influence of meth when he forced the woman to drive throughout the night.  Officials say after 12 hours, police were able to use GPS technology to track down the vehicle and arrest the suspect.  His grandmother wasn't injured.