(Portland, OR)  --  A Washington County school bus driver is facing child pornography charges.  Police arrested 40-year-old Michel Shanon Harmon Saturday on charges of transportation of child porn and one count of possession of child porn.  Police say a search of his electronic devices turned up nearly four-thousand images and more than 300 videos, some of which investigators say were violent and extremely graphic in nature.  Harmon drove Bus 23 for Lake Oswego Junior High and Oak Creek Elementary School.