Adair County Unsolved The National Missing and Unidentified Persons System (NamUs) Dennis Morrison Missing since September 1999 Dennis Morrison disappeared around September, 1999. He was last known to be driving a gray Oldsmobile Delta 88. Morrison’s vehicle has never been recovered. Police believe Morrison was murdered. The photo to the right shows scarring to Morrison’s jaw from a prior gunshot wound. Anyone with information about Morrison’s whereabouts can make an anonymous call to the DA’s hotline at (918) 772-7568.