Retired agent Joe Pistone served in the FBI for nearly 27 years.  However, he is primarily known world-wide for the six years he spent infiltrating one of the New York mafia families as Donnie Brasco, his undercover alter ego. In this episode of FBI Retired Case File Review, he reviews his undercover assignment, a mission so secret only a handful of agents knew what he was doing and where he was as he secretly gathered vital intelligence on the mafia and its criminal ways. The work Joe Pistone did was so incredibly dangerous that it has been documented in numerous books, documentaries, television shows, and the 1997 feature film Donnie Brasco, starring Johnny Depp and Al Pacino. After the undercover case was closed, Joe spent the remainder of his Bureau career testifying in federal court all around the country for mob related trials and at the FBI Academy helping to establish the FBI's undercover program and training courses. Joe continues to travel overseas lecturing and training law enforcement officers how to "go undercover."