• Dario Argento is back in great Giallo horror tradition just one year after his debut.
  • Ennio Morricone returns working again with Argento (and though the tone is different—Morricone is another bridge between the Spaghetti Westerns and Giallo horror).
  • Argento’s camera tracks forward in his now trademark point-of-view style- pushing through doors
  • A marvelous cinematic and formal touch employed by Argento is the closeup of the eyeball (of the killer- not to reveal the killer’s identity of course). Argento splices to it at least eight to ten times.
  • A blind man witnesses the murder (a great Karl Malden)- and of course he is a former journalist. As the POV murders rack up the “maniac theory” is suggested. They use genetic testing for a XYY gene—common in serial killers.
  • De Palma certainly shares the genre (whether he is Giallo or not depends on who you talk to)- but with the split diopter (a stunner at the 78/79-minute mark- great depth of field shot  with James Francisus’ Carlo in the background left- above) seedy/murderous content, tracking point of view camera movement—there are many similarities (Argento predates De Palma’s use of these).
  • Though Mario Bava is the greater overall influence, one can feel Blow-Up again here just like in Argento’s The Bird with the Crystal Plumage. Here, a photo of the murder is blown up again.
  • The title is about the number of suspects.
  • Big, bold, beautiful gawdy 1970s wallpaper
  • a stairwell showoff scene at the 60-minute mark
  • poisoned milk just like Hitchcock
  • flickering scene transitions just like 1969’s Easy Rider
  • Recommend but not quite in the top 10 of 1971