(1971)

Submitted by Patay

Roberto’s (Michael Brandon’s) own wife Nina (Mimsy Farmer) is the killer and the one behind the whole thing.

Nina hired Calisti (Carlo Moroni) to stalk Roberto and set up his “murder” to blackmail Roberto apparently because Roberto reminds her of her abusive father who committed her to a lunatic asylum when she was a little girl. Nina kills Calisti (for real) to prevent him from telling Roberto about her plans.

Roberto never finds out about the phony Calisti killing but discovers Nina’s true colors when he discovers that she wears a distinctive necklace with the shape of a fly carved in it which resembles the photograph of the last vision taken from the latest victim’s retinal eyes. Nina flees but gets decapitated in a car accident trying to escape.