"Fox" is the call-signal for all units based at Grønland police precinct in the centre of Oslo.
Before producing the first season, writer/producer Jens Øvrebø and writer Rift Fournier (the latter known for shows like Kojak (1973) and Matlock (1986)) drove around in Oslo with the local police for research.
The first season had a budget of 40,000,000 NOK (roughly $6,000,000).
Background policemen are often played by real uniformed police.
Season 1 finally (directed by Thomas Kaiser) was nominated to "Gullruten" (norwegian Emmy) in 2002 for best TV-drama.