Twitch of the Death Nerve

A Bay of Blood is a 1971 Italian giallo film directed and co-written by Mario Bava and starring Claudine Auger, Luigi Pistilli, Claudio Camaso, Laura Betti, Leopoldo Trieste, Anna Maria Rosati, Brigitte Skay, Chris Avram and Isa Miranda. The story details a string of mysterious murders that occur around the titular bay.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.

Poster © the film's rights holders.