The Departed
Release date: Sep, 26th 2006 (US)

To take down South Boston's Irish Mafia, the police send in one of their own to infiltrate the underworld, not realizing the syndicate has done likewise. While an undercover cop curries favor with the mob kingpin, a career criminal rises through the police ranks. But both sides soon discover there's a mole among them.
Director: Martin Scorsese.
Starring: Jack Nicholson, Leonardo DiCaprio, Matt Damon, Mark Wahlberg, Vera Farmiga, Martin Sheen and more.