David Hemmings

Marcus Daly

Daria Nicolodi

Gianna Brezzi

Gabriele Lavia

Carlo

Macha Méril

Helga Ulmann

Eros Pagni

Supt. Calcabrini

Giuliana Calandra

Amanda Righetti

Piero Mazzinghi

Bardi

Glauco Mauri

Prof. Giordani

Clara Calamai

Marta

Aldo Bonamano

Carlo's Father

Liana Del Balzo

Elvira

Vittorio Fanfoni

Cop Taking Notes

Dante Fioretti

Police Photographer

Geraldine Hooper

Massimo Ricci

Jacopo Mariani

Young Carlo

Furio Meniconi

Rodi

Fulvio Mingozzi

Agent Mingozzi

Lorenzo Piani

Fingerprint Cop

Salvatore Puntillo

Police Agent

Piero Vida

Fat Cop

Nicoletta Elmi

Olga

Dario Argento

Murderer's Hands (uncredited)

Salvatore Baccaro

Fruit Vendor (uncredited)

Omero Capanna

Hitman (uncredited)

Bruno Di Luia

Concerned Man in Restroom (uncredited)

Attilio Dottesio

Florist (uncredited)

Tom Felleghy

Surgeon (uncredited)

Glauco Onorato

(uncredited)

Marilù Tolo

Carol (archive footage) (uncredited)

Franco Vaccaro

Pietro Valgoi (uncredited)

Gianni Di Segni

Rabbi (uncredited)

Marc Smith

Professor Giordani (voice)

Mario Pascucci

Library Caretaker (uncredited)