(Oregon City, OR) -- A man convicted of using a gun to rob a Denny's with video lottery games in Happy Valley has been sentenced to 14 years in prison. Clackamas County prosecutors say Douglas Kelsey saw an employee removing cash from video games, he grabbed the bag of money and pointed a gun at employees and customers before leaving. Kelsey was also sentenced for assaulting an inmate while in jail. Kelsey pleaded guilty to Robbery in the First degree and assault. He has several prior convictions for violent crimes.