Estamos en los Estados Unidos de los años 30, donde los mafiosos campan a sus anchas por los barrios. Todo cambiará cuando se forme la primera policÃa federal del paÃs a las órdenes de Edgar Hoover. Los principales capos se enfrentarán con todas sus armas contra la recién creada agencia contra los criminales.
 | Johnny Depp | John Dillinger |
 | Christian Bale | Melvin Purvis |
 | Marion Cotillard | Billie Frechette |
 | Billy Crudup | J. Edgar Hoover |
 | Stephen Lang | Charles Winstead |
| Jason Clarke | John 'Red' Hamilton |
| Stephen Graham | Baby Face Nelson |
 | Stephen Dorff | Homer Van Meter |
| Rory Cochrane | Agente Carter Baum |
| Adam Mucci | Agente Harold Reinecke |
| Branka Katic | Anna Sage |
 | John Ortiz | Phil D'Andrea |
| Lili Taylor | Sheriff Lillian Holley |
 | Giovanni Ribisi | Alvin Karpis |
 | David Wenham | Pete Pierpont |
| James Russo | Walter Dietrich |
| Peter Gerety | Louis Piquett |
| Michael Bentt | Herbert Youngblood |
| Alan Wilder | Robert Estill |
| Kurt Naebig | Agente William Rorer |
| Shawn Hatosy | Agente John Madala |
| Domenick Lombardozzi | Gilbert Catena |
| Bill Camp | Frank Nitti |
 | Channing Tatum | Pretty Boy Floyd |
| Spencer Garrett | Tommy Carroll |
| John Michael Bolger | Martin Zarkovich |
| Christian Stolte | Charles Makley |
| Michael Vieau | Ed Shouse |
| Richard Short | Agente Sam Cowley |
| Randy Ryan | Agente Julius Rice |
| John Hoogenakker | Agente Hugh Clegg |
 | Leelee Sobieski | Polly Hamilton |
| Rebecca Spence | Doris Rogers |
| Ed Bruce | Senador Kenneth D. McKellar |
| Gareth Saxe | Agente Ray Suran |
| Matt Craven | Gerry Campbell |
| Don Frye | Clarence Hurt |
| Carey Mulligan | Carol Slayman |
| Emilie de Ravin | Barbara Patzke |
| Chandler Williams | Clyde Tolson |
| Geoffrey Cantor | Harry Suydam |
| David Warshofsky | Guardia Baker |
| Joseph Mazurk | Guardia Bryant |
| Don Harvey | Cliente de Steuben Club |
| Diana Krall | Cantante |
