Aimilia, the Psychopath(1974)

Original title: Αιμιλία, η διεστραμμένη

Aimilia, a young and relatively well-to-do woman, leads a rather schizophrenic existence. Every day, she gives piano lessons to the children at an orphanage, while at night she brings home a series of lovers whom she picks up at random and whom she kills while in a sexual frenzy.