In one of the shots of the third victim lying in the morgue, she has her eyes open and she blinks.
An actress posing as a corpse of a second woman shifts when she's being caressed on an autopsy table, likely a motion of recoil.
As the inspector goes through the murderer's newspaper clippings, the English translation superimposed over Italian headlines mistranslates the Italian "amante" as "lower", a misspelling of the proper translation, "lover."
How the killer managed to get all the photos of the clandestine rendezvouses of all of his many victims is never explained.