John M. DeHart - is a video game producer. John M. DeHart began his career in 2008 and has worked for companies such as Treyarch and Activison. John M. DeHart's first game was Call of Duty: World at War which was released 12 years ago. Best Game John M. DeHart contributed to was Call of Duty: World at War. John M. DeHart's latest work is Call of Duty: World at War which was released 12 years ago.