Upon it announcement, the film drew opposition from some of the people affected by the case in real life, including the parents of some of serial killer Michel Fourniret's victims, who felt the film would glorify the killer and make them relive their most painful moments. One of the most vociferous voices raised against the film was Fourniret's son Selim, who tried to stop the film from being broadcast. In response, while director Yves Rénier questioned Selim's motives, producer Franck Calderon stated that the team reassured the families that reached out to them and that the film doesn't contain any violent reenactments but is a fact-based narrative focused on the police investigation of the case.