Gloria Trevi started as really supportive for the film while it was getting made (she even met up multiple times with the director and the writer), but after watching the final cut, Trevi named it "aberrant".
Sofía Espinosa took singing lessons in order to sing like Gloria for the movie.
Sofía Espinosa never met Gloria.
The director and the writer did 9 years of research and more than 30 hours of interviews to Trevi, Andrade, Paty Chapoy and ex-members of the Clan.
Features some of Trevi's songs (but sang by Sofía Espinosa) from "Dr. Psiquiatra", "La Papa Sin Catsup" to "El Recuento de los Daños" among others.