The main location of the series is Stockholm, but most of it is shot in Gothenburg.
Season 1 is based on Leif G.W. Persson's novel "Kan man dö två gånger?" and parts of his novel "Den som dödar draken". Season 2 is based on Persson's novel "Den sanna historien om Pinocchios näsa".
There are several references to Moomins and Hattifatteners. These are characters from a series of books and a comic strip by Finnish author Tove Jansson. The Moomins are the central characters; the Hattifatteners are secondary ones. The Hattifatteners are unusual characters, and a comparison to them may be taken as derogatory. Several television series and films are based around the Moomins' world.
Bäckström was previously played by Claes Malmberg in En pilgrims död (2013) and Le Quatrième Homme (2014), both of which also feature Kjell Bergqvist in another role.