
Ritchie Coster
Ritchie Coster is an English character actor. He is best known for playing the roles of Dietrich Banning in The Tuxedo (2002), the Chechen in The Dark Knight (2008), Elias Kassar in Blackhat (2015), Mayor Austin Chessani on the second season of the HBO anthology television series True Detective and Francisco Scaramucci / Mr. Blue on the SyFy television series Happy! Since 2025, he has been part of the main cast of the CBS drama series Watson.