Brian Helgeland has written screenplays for multiple films.
Brian Helgeland . He is most known for writing the screenplays for L.A. Confidential ( for which he received the Academy Award for Best Adapted Screenplay ) , Mystic River , and A Nightmare on Elm Street 4 : The Dream Master . Helgeland also wrote and directed 42 ( 2013 ) , a biopic of Jackie Robinson , and Legend ( 2015 ) , about the rise and fall of the Kray twins .