Jackie DiNorscio picked Vin Diesel to play him. Much to Diesel's surprise, DiNorscio wanted Diesel cast after watching The Fast and the Furious (2001).
Sidney Lumet made Diesel come to the table reads in full make-up, to make it easier for the rest of the cast to react to Diesel in character.
T.J. Mancini obtained official transcripts from the trial and added it as dialogue for the court-room scenes.
The court case on which this film is based is the longest criminal case in United States judicial history.