Dennis the Security Guard Gender: Male Portrayed by: Michael Maize First Appearance ● NCIS: Yankee White (episode). Last Appearance ● NCIS: Yankee White (episode). List of Appearances Dennis the Security Guard is a TSA Guard assigned to the Ronald Reagan Washington National Airport in Washington D.C. BiographyEdit Pre-SeriesEdit NCIS Season 1Edit Categories: Americans One-Off NCIS Characters Articles whose full names are not known Civilians Add category Cancel Save