Police are looking for 20-year-old Derrick A. Cooper, who was last seen at 2306 Montgall Ave. yesterday, July 14. He left that address on foot between 1 p.m. and 9 p.m., and his destination was unknown. Derrick is a black male with black hair and brown eyes who is 6 feet 1 inches tall and weighs about 180 pounds. He was last seen wearing a black shirt, red shorts and black shoes. Derrick reportedly is unable to care for himself and may become violent without medication. If you have any information about Derrick's whereabouts, call KCPD's Missing Persons Section at 816-234-5136 or 911.