First episode had 1,591,000 viewers in Denmark
The actors spent time at Denmark's police academy before filming began, learning about investigation techniques as well as training abilities to act like real police officers in action scenes.
David Owe's part was originally meant for a "classic", overweight, chainsmoking, coca cola-drinking geek, but after his audition the part was rewritten to fit him.
The town that is shown in Hallgrim's flashbacks is actually a fishing town located on a island just on the south coast of Iceland. The island, Vestman-Island, is also shown a great part in season 2.
Accident struck the filming of this series only two weeks into the shooting as one of the leading actors, Jens Albinus, tripped on stage while performing in a play in Copenhagen and broke his leg.