* AdaptationDisplacement: Many people aren't even aware this film is based on a novel.
* CompleteMonster: [[SerialKiller Bob Rusk]] is one of the most deranged villains in an Creator/AlfredHitchcock film. Known as the "Necktie Murderer," Rusk is implied to rape his victims, before graphically strangling them to death with his tie. Rusk displays his violent compulsions multiple times, but even frames one of the only supposed friends he has for the murders with a dead woman's item, perfectly willing to let innocents take the fall for him.
* JerkassWoobie: Richard Blaney, he's definitely a MeanBrit, but is WronglyAccused of being the Necktie Killer and lost the two women in his life who understood him, Brenda and Babs, to the real killer - his own friend Rusk.
* {{Narm}}: The tongue sticking out. Apparently meant to accentuate the horror of the scene, but it just looks comical.