Director Baran bo Odar has said that South Korean movie Memories of Murder (2003) was a big inspiration for this movie.
The seemingly obvious reference to Fargo (1996), having Jule Böwe play a pregnant cop, is in fact not a reference. When she auditioned for the part it wasn't known she was pregnant. It wasn't until she got the part that she told the director she was three months pregnant, when she in fact was six months pregnant. In the end the director liked the idea and decided to write it into the script.
The license plates seen throughout the film are fake, no German city/county has ever issued plates starting with FA.
Director Baran bo Odar, along with the films cinematographer, watched several westerns before shooting this picture. This was to give the movie more of a western style to it instead of being just another thriller.
Charly Hübner's role as Roman Mittich was cut for the final theatrical release. The actor got a 'thanks' credit, though.