A Miami native himself, Barnwell is the head coach at Miami Carol City Senior High School with 13 total years of coaching experience. He served as Carol City Senior’s defensive coordinator before being named head coach in 2008. His Carol City Chiefs were back-to-back district champions in 2008 and 2009 and advanced to the regional semifinals of the Florida state playoffs. Players who Barnwell has formerly coached include brothers Santana and Sinorice Moss who both went on to play at the University of Miami and the National Football League.