A grueling manhunt stretches into a third day Monday for a suspect in an interstate shooting that struck 12 vehicles and wounded five people in Kentucky. Authorities are vowing to keep up a relentless search as the stress level remains high in a rural area where some schools canceled classes. Authorities have searched a rugged area of southeastern Kentucky since Saturday evening. That's when a gunman began shooting at drivers on Interstate 75 near London, a small city of about 8,000 people. The search was temporarily suspended once darkness fell Sunday night, but is set to resume Monday. Joseph A. Couch has been named a suspect in the shooting.