Ninetto Davoli, who plays Epifanio in this film, has acted in many of Pier Paolo Pasolini's films and was, for a period of time, his lover. He is also a character in the film, played by Riccardo Scamarcio.
Both Willem Dafoe and Riccardo Scamarcio have played roles in the John Wick franchise. Dafoe appearing as Marcus in John Wick (2014) and Scamarcio has Santino D'Antonio in John Wick: Chapter 2 (2017).
Francesco Siciliano also appeared in Pasolini, un delitto italiano (1995), which covered the same case. His parents also worked as an actors in Pasolini's movies. Enzo Siciliano in Das 1. Evangelium - Matthäus (1964), and Flaminia Siciliano in Große Vögel, kleine Vögel (1966).