Matti Kassila's films Inspector Palmu's Error (1960) and Gas, Inspector Palmu! (1961) were both based on Mika Waltari's novels. Because of there was no third novel, Kassila asked Waltari to write a screenplay to a new Palmu-movie. Waltari agreed. Three weeks later Waltari phoned Kassila and apologized that he couldn't write a script of a movie. Instead of that he had wrote a new Palmu-novel. That novel was published and Kassila wrote a screenplay with Kaarlo Nuorvala for the new Palmu-movie.
Tähtitorninmäki is an ancient observatory district from 19th century - it literally means Hill of Observatory in Finnish.
The homicide took place on 19th of May 1962. The tabloid where homicide is established dates to 20th of May.