The film's three stars were each born nine years apart from each other: Seymour Cassel in January 1935, Sondra Locke in May 1944, and Colleen Camp in June 1953.
The film was finished in 1974, but not released to theaters until 1977. It might never have been released at all if not for Sondra Locke's career-boosting appearance in the film The Outlaw Josey Wales (1976), which she made one year after this film in 1975.
Colleen Camp was almost 10 years younger than Sondra Locke was, yet played Donna, a character of similar age.
According to an interview with the film's lead actress, Sondra Locke, for a film podcast titled The Projection Booth, the film was originally supposed to have a more sinister and darker tone and everyone was excited to do it. But then the original director got replaced as soon as the shoot started and the new director, Peter S. Traynor, had a different idea of what the film should look like. This caused serious clashes on the set throughout the whole shoot between the cast and crew and the new director. The crew believed that he did not know what he was doing when it came to directing and he did not understand the story, which caused him to often be absent-minded on set. Tensions remained high during the shoot. Locke said the cameraman antagonized her for days until she finally told him she did not want to hear any more of his snide comments. He told her what she could do with herself and she slapped him. He tried to slap her back, but she dodged him and they got into a screaming match that sent the whole crew running. The makeup man was fired, and the cast and crew, led by editor-cinematographer David Worth, took every opportunity to convince Traynor to let them do their own thing. Seymour Cassel was especially angry at the way that Traynor was doing things. The pair often had volatile arguments and by the end of the shoot, Cassel almost punched Traynor in the face. After this incident, Cassel decided to quit the shoot, since his scenes were already completed. After principal photography wrapped, Cassel refused to come back to re-record some dialogue, so his character ended up being entirely re-dubbed by an uncredited Worth. Eventually, due to such a toxic atmosphere on the set, no one was particularly pleased with the way the film turned out. The fact that the film became a cult hit surprised Locke, since she never liked it, which is the main reason why she agreed to support the idea of a remake which was titled Knock Knock (2015) and was released three years before she died. While much has been written over the years about Locke being too old to play Jackson, it should be noted that the public was unaware of her true age back then, since she and her publicists always lied about it, and she even fudged her date of birth on official documents.
Audiences laughed when Jackson said in the film that she was 17, as Sondra Locke, the actress playing her, had noticeable wrinkles on her face.