The filming of this and Inimigo Público nº 1 (2008), which lasted nine straight months, was done in reverse chronological order so that Vincent Cassel could progressively lose the weight he gained in preparation of the role, as Cassel knew he couldn't gain weight while filming.
Just like Vincent Cassel, Samuel Le Bihan gained 20 kgs (44 pounds) for his role as gangster Michel Ardouin.
Vincent Cassel gained 20 kgs (44 pounds) for the role during the four months leading up to the shoot.
Filmed back-to-back with Inimigo Público nº 1 (2008), which stands as the first half of the two-part story.
Producer Thomas Langmann first contacted Vincent Cassel about the Mesrine project in 2001, after the release of Jacques Audiard's Sobre Meus Lábios (2001). Cassel initially accepted, but then bowed out as he found the script too "black and white". Benoît Magimel and Vincent Elbaz convinced by new helmer Jean-François Richet were then successively attached before Cassel returned, and especially Abdel Raouf Dafri's two-part script, claiming the screenwriter had succeeded in bringing the right tone to the picture and the character, bringing out all his darkness and paradoxes.