The Mendocino County Sheriff’s office is investigating the disappearance of a Willits man. Riley Hsieh (Shay) was last seen on security camera footage on Monday morning. He is known to frequent the end of Hawk Terrace Hill but has not been found there or at his residence. Hsieh is 24, 5 feet 10 inches tall and 130 pounds and was wearing a gray robe, light blue pants and carrying a light blue or green bag. Anyone with information is asked to contact the Sheriff’s office.