(Tigard, OR)  --  Police are investigating reports of vandalism involving at least eight homes and cars in a neighborhood in Tigard.  Authorities say the vandalism spree happened between 4:30 and 5:45 yesterday morning in the city's Castle Hill neighborhood, and at several homes in the surrounding area.  Police say obscene messages were spray-painted on garage doors and cars.  There's no word on the cost of the damage done.