A Bay of Blood (1971)
Directed by Mario Bava. With Claudine Auger, Luigi Pistilli, Claudio Camaso, Anna Maria Rosati. An elderly heiress is killed by her husband who wants control of her fortunes. What ensues is an all-out murder spree as relatives and friends attempt to reduce the inheritance playing field, complicated by some teenagers who decide to camp out in a dilapidated building on the estate.