Frenzy (1972)

In Alfred Hitchcock's first and only R-rated film (and the only film that showed nudity) - a typical thriller:

• in the film's opening, a nude female body was floating face-down in the Thames River - the first seen "Necktie" victim
• in the film's first major scene, the long and intense necktie rape-strangulation scene of ex-Mrs. Brenda Margaret Blaney (Barbara Leigh-Hunt), who was confronted by charming ladies man Mr. Bob Rusk (Barry Foster) in her office: "You're the one I wanted to see....I like you. You're my type of woman"; she suffered a brutal death (a montage composed of a flurry of brief shots); when she begged for her life, he tore off her dress and bra (exposing one breast), screamed at her: "Love me!...Women - they're all the same", and then revealed that he was the notorious Necktie Killer - an impotent serial killer; after a lengthy struggle, she was left dead with her twisted tongue hanging out

Bab's Necktie Rape-Strangulation Sequence

• the brilliantly-executed, incredible staircase shot (a lengthy backwards tracking shot from Rusk's apartment) in which the camera slowly retreated from a closed doorway behind which another 'necktie' rape/strangulation murder was taking place of barmaid Barbara Jane ('Babs') Milligan (Anna Massey) - and then proceeded down the stairs and out into the brightly-lit street where pedestrians were unaware of the horrors inside
• the tense scene of the killer Bob Rusk frantically searching through a stack of burlap potato sacks in the back of a moving, jostling and swerving truck to find his missing, incriminating initialed/monogrammed stickpin (clenched in a death grip by the nude corpse of Babs in a state of rigor mortis) torn from his lapel while she struggled - Rusk had to snap the corpse's clutching fingers to retrieve it

The Potato Truck Sequence: Rusk's Incriminating Initialed/Monogrammed Stickpin Clenched in Hand of Corpse in Back of Truck

• the scene of the Chief Inspector's wife Mrs. Oxford (Vivien Merchant) crunching on a breadstick as her husband Chief Inspector Oxford (Alec McCowen) explained the breaking of the corpse's fingers in the truck while he was attempting to eat her inedible 'gourmet' meal: ("Obviously he was looking for something....The corpse was deep in rigor mortis. He had to break the fingers of the right hand to retrieve what they held... It had to be something that would incriminate him. Something that he missed when he put the body on the truck. A monogrammed handkerchief, perhaps")
• the final scene in Rusk's apartment bedroom where framed necktie-murderer Richard "Dick" Blaney (Jon Finch) had fled after escaping from prison to kill Rusk; he beat a figure under bedclothes (thinking it was Rusk) with a crowbar, until he realized that the body belonged to an anonymous nude female (Susan Travers) (another strangulation victim murdered earlier off-screen, with contorted features: rolled-back eyes and a curved tongue) when her arm with bracelets dangled off the side of the bed; Chief Inspector Oxford apprehended Blaney at the scene - who was now fully implicated, but then heard someone else lugging a large trunk up the stairs; both remained quiet as necktie murderer Bob Rusk was tricked into being cleverly apprehended after entering (with the damning evidence in his own bed). Oxford noted to Rusk in a clincher line of dialogue: "Mr. Rusk, you're not wearing your tie"