It's the late 1980s and low-level mobster Jackie DiNorscio (Vin Diesel) has just been shot by his junkie cousin Tony Compagna (Raúl Esparza), but refuses to press charges against him to police. Jackie soon gets arrested and is sentenced to thirty years on an unrelated drug bust.
Tony, afraid of reprisals from the extended mob family run by Nick Calabrese (Alex Rocco), agrees to be a government witness for district attorney Sean Kierney (Linus Roache), who intends to bring down dozens of organized crime figures all at once. Kierney tries to bribe Jackie to be a government witness as well, but it's not in the gregarious Jackie's nature to be a rat.
That sets in motion a massive court case where Jackie, Nick and dozens of other mobsters are tried together for a countless number of crimes in front of presiding Judge Sidney Finestein (Ron Silver). Upset with his current lawyer, who couldn't even keep him from doing a 30-year stretch, Jackie turns down an offer to be represented by lead defense attorney Ben Klandis (Peter Dinklage) and decides to represent himself in court, despite having no legal background or any real knowledge of how to proceed.
Jackie's mischievous and vulgar manner amuses the jury on occasions but persistently irritates the judge, lawyers, witnesses, and defendants, including his friends from the mob. As weeks turn into months, the court case evolves into a marathon affair. Ben begins to believe that maybe Jackie could be effective, but Nick Calabrese is furious and Judge Finestein repeatedly threatens the charismatic mobster with contempt of court.
Jackie's estranged wife, Bella (Annabella Sciorra), visits him in jail, where he is becoming increasingly frustrated. Guards spy on him and prosecuting attorneys remove his favorite chair, causing considerable pain to Jackie's injured back.
He apologizes to the court and tries to mind his manners in the end. The prosecutors and the defense return to their offices expecting the jury to deliberate for at least a week. However, the jury comes to a decision after only 14 hours of deliberation. The jury reaches a verdict of not guilty for all. The entire courtroom reaches pandemonium as the family celebrates. The entire family hugs the twelve jury members as they leave. Meanwhile, Jackie is the only one bound for jail, returning there to finish his sentence. Jackie is welcomed as a hero in the correctional facility, where fellow prisoners chant "Jackie" and extend their hands in tribute to a man who refused to compromise his family for his life.
Vin Diesel as Jackie DiNorscio
Peter Dinklage as Ben Klandis
Linus Roache as Sean Kierney (Samuel Alito)
Ron Silver as Judge Sidney Finestein
Annabella Sciorra as Bella DiNorscio
Alex Rocco as Nick Calabrese (Anthony Accetturo)
Jerry Adler as Rizzo
Raúl Esparza as Tony Compagna
Richard Portnow as Max Novardis
Aleksa Palladino as Marina DiNorscio
Robert Stanton as Chris Newberger
Marcia Jean Kurtz as Sara Stiles
Domenick Lombardozzi as Jerry McQueen
Josh Pais as Harry Bellman
Peter McRobbie as Peter Petraki
Chuck Cooper as James Washington
Frank Pietrangolare as Carlo Mascarpone (Michael Taccetta)
Richard DeDomenico as Tom "Nappy" Napoli
Jerry Grayson as Jimmy "The Jew" Katz
Tony Ray Rossi as Joe Bellini
Vinny Vella as Graziedei
Paul Borghese as Gino Mascarpone (Martin Taccetta)
Frank Adonis as Phil Radda
Nick Puccio as Alessandro Tedeschi
Frankie Perrone as Henry Fiuli
Salvatore Paul Piro as Mike Belaggio
James Biberi as Frank Brentano
Oscar A. Colon as Pissaro
Ben Lipitz as Henry Kelsey
Steven Randazzo as Chris Cellano
Gerry Vichi as Theodore
Louis Guss as Court Clerk
Gene Ruffini as Giacomo DiNorscio, Sr.
Roger Zamudio as Octavio Juarez
Terry Serpico as Michael Kerry
Mark Kachersky as Agent Brandon
Frank Lentini as Charley Kraus
Antoni Corone as Detective
Dennis Paladino as Sylvester
David Brown as US Marshall #1
Louis Mustillo as US Marshall #2
John DiBenedetto as Jesse
Eddie Marrero as Guard
based on the true story of the longest Mafia trial in American history
Much of the courtroom testimony was taken from the original court transcripts.