Leroy Jethro Gibbs is a fictional character of the CBS TV series NCIS, portrayed by Mark Harmon. He is an ex-Scout Sniper for the United States Marines turned Special Agent who commands a team for the Naval Criminal Investigative Service. Gibbs is the most accomplished marksman on the team and the most skilled at handling violent standoffs; he depends on his other agents heavily for technical forensics and background checks. He is patient but firm with his team and has little patience for bureaucracy; he commands most other main characters - especially Anthony DiNozzo, Timothy McGee, Eleanor Bishop, Ducky Mallard, and Abby Sciuto - and is the backbone of the cast.