The use of the color red was very controlled during production, appearing only when Liz is present (such as the high school auditorium and her home) or during the murders.
In the opening high school scene, Katharine (Franca Raisa) is reading a book titled "Dusk", a spoof of the "Twilight" series. The cover depicts a hand holding up a blood red cherry, which was an in-joke about the themes of virginity and sexuality in the movie.
The family portrait of Ashley and her parents was made intentionally tacky, as the director wanted to show the family had poor taste despite their wealth. The role of Ashley's father (who can also be seen briefly during the cocktail party) was played by Christopher Gourlay, the film's Location Manager.
A slow motion shot of the mothers and Liz Batho near the end of the film was actually an accident: the shot was supposed to be at normal speed but the camera's frame rate was over-cranked, and no one noticed until the film was developed. When the director saw it in the dailies the next day he decided he like the slow motion better and it was kept in the movie.
The film takes place in the fictional town of San Griento; the word sangriento means "bloody" in Spanish.