who is the movie the departed based on
The Departed Nicholson, however, wanted the film to have "something a little more" than the usual gangster film, and screenwriter Monahan came up with the idea of basing the Costello character on the famous Irish-American gangster Whitey Bulger from Boston. This gave the screenplay an element of realism â€“ and also an element of dangerous uncertainty, because of the wide-ranging carte blanche the FBI gave Bulger in exchange for revealing information about fellow gangsters.[4] A technical consultant on the film was Tom Duffy, who had served three decades on the Boston Police Department, particularly as an undercover detective investigating the Irish mob.[12][13]