Loosely based on the story of the so-called Monster of Florence, both this and [link-tt0088745] use the same visual motif of car windows shattering in slow motion after being shot by "The Monster."
The scene of the first murder was shot in the actual Scopeti clearing, where the real murder had occurred.
The film caused multiple scandals already before coming out: cinema operators in Florence refused to show it, and a magistrate banned it from being played in Toscania, where the crimes had occurred. The magistrate even ordered all the scenes showing the murders to be removed from the picture, before he would even consider allowing it to be released.