Sisters (1973)

Grace Collier, a fiery columnist for the Staten Island Panorama known for her hard-hitting stories, finds herself ensnared in a chilling mystery when she witnesses the brutal murder of a man from her apartment window. The victim, desperately trying to etch the word "help" in his own blood, locks eyes with her before he's silenced forever by a white woman. Despite her conviction, the police, harboring disdain for her previous exposés on their brutality and racism, dismiss her claim. When Grace and the police investigate the apartment from which the crime was staged, they find no trace of the horrific scene she describes. Instead, they encounter Danielle Breton, a French-Canadian model and actress on the brink of divorce from her husband, Emil. However, the reality is more sinister. The murderess is none other than Danielle's possessive twin, Dominique Blanchion, with Danielle's recent acquaintance and lover, Phillip Woode, as the unfortunate victim. With Emil's aid, they hide the crime. Undeterred, Grace employs the assistance of private investigator Joseph Larch to unravel the tangled web of deception. Grace is convinced the body couldn't have vanished in the short span between her witnessing the murder and their arrival at the scene. As they dig deeper, they uncover a twisted psychological triangle between Danielle, Dominique, and Emil, marked by the scar etched onto Danielle's hip. However, as they edge closer to the truth, they find themselves in the crosshairs of Emil, a man willing to pay any price to guard their horrific secret. In this gripping tale, Grace must rely on her journalistic instincts and courage to reveal the truth and bring justice, even when the authorities refuse to believe her.

Sisters is a horror movie featuring Margot Kidder and directed by Brian De Palma.

Sisters is currently streaming for free (ad-supported) on Plex and Plex Player and it's also available on Criterion Channel, Max and Max Amazon Channel.

It is also possible to buy Sisters on Amazon Video and Apple TV.