Sisters (1973)

When journalist Grace Collier witnesses her neighbour Danielle apparently kill a man, police find no evidence, so she hires a private investigator and unearths a disturbing secret from Danielle's past.

This early 1970s psychological thriller from director Brian De Palma blends horror and mystery as a journalist's murder report is dismissed by police, pushing her to hire a private eye and dig into the model's hidden history. Margot Kidder stars as the enigmatic Danielle, with Jennifer Salt as the determined Grace and Charles Durning among the supporting cast. A tense, twist-laden tale of secrets and split identities.