I saw this on late night TV and fell in love with it. It starts with a great, weird opening credit sequence and contains a music score credited to "Frank Mason" that you will find yourself humming all through the rest of the movie (and maybe the rest of your life). It also has great color photography and atmospheric dark lighting which all works together to create a scary mood before the movie even gets going good. Too bad almost no one else I've met has ever heard of this film. My girlfriend and I really enjoyed it, although she got very mad at me for humming the title theme while she was trying to listen to the dialogue. Oh, what I wouldn't give for a laserdisc of this movie.
Actually it turns out the composer of the great music score is an Italian by the name of Francesco De Masi and he also did the score for the movie THE GHOST (1963). There is a scene in the beginning with a couple in bed that got cut out of the TV version even though it doesn't really show anything and in fact, I think the first murder may have been cut. Luckily, there is now a soundtrack CD but it is not officially available on DVD yet, and there are some really lousy prints floating around out there. I am not sure the Anglicized credits are imposed on the film by the American or British distributor or if the Italian production company pulled a "Riccardo Freda" and tried to make it seem like the film was made in England or America by giving the crew American-sounding names.