Colonel MacKenzie joined the Canadian Forces Reserves in 1985 as a private in the Seaforth Highlanders, based in Vancouver. In 2005 he assumed command of the regiment in the rank of Lieutenant Colonel. Since then he has served two one-year overseas tours, returning to Canada in December, 2011 after serving in the role as an Operations Coordinator. Late in January, 2012, he resumed his duties as a member of the Vancouver Police Department.