After the success of Sharon Stone's Basic Instinct (1992), this film was retitled in German as "Final Instinct".
The script was written originally to be an episode of Alfred Hitchcock Presents (1955). Co-writer of that script, Frank De Felitta expanded that unsold and unmade screenplay and it became his last credit as a director.
The second time Sharon Stone and Ronny Cox star together in a movie, the first one being in Total Recall (1990).
The trapped in the apartment scene was originally used in the 1955 Ida Lupino "Official Films" TV show. Every detail of the situation was copied in the film, right down to the thin spatula that served no purpose in the Scissors film.
Near the beginning of the film, the man behind the desk at Angela's apartment building is reading a paperback copy of the 1975 novel "Audrey Rose" by Frank De Felitta which was made into the film Audrey Rose (1977). He also wrote that screenplay - and the one for this film, too.