The book the film is based on chronicles the murder of Kitty Genovese. The film distances itself from the true story somewhat by transposing the action to contemporary France and changing the characters.
In early January, Charlotte Gainsbourg and Nathalie Baye were announced to be part of the cast, however by the time filming started a few weeks later, both had dropped out. Gainsbourg, due to being pregnant with her and Yvan Attal's third child, was replaced by Sophie Quinton, while Nicole Garcia took on Baye's role.