The door-less elevators at the Berlin police headquarters are what is known as a "Paternoster lift". The lift consists of a continuously moving loop of low-speed elevator cars, one half moving up while the other half moves down. Common in European buildings prior to World War II, a large number of these have been preserved in Germany. Most surviving lifts are however no longer in general use due to their obvious safety issues.
Most expensive non-English-language TV series ever made and also the most expensive German TV series ever with a budget of approximately 40 million Euros.
The character of Alfred Nyssen is loosely based on real-life industrialist Fritz Thyssen.
Production designer Uli Hanisch paid homage to his famous colleague Ken Adam. Adam was born in Berlin as Klaus Hugo Adam and was Jewish. His father, Fritz Adam, was a department store owner and had to flee the Nazis in 1934, but certain things had to be left behind. Among them plans for a huge shopping mall, which Hanisch now used for the film set. On the Art Deco facade can therefore be seen Adam & Sons.
Various episodes contain deliberate but subtle musical anachronisms consisting of songs originally recorded by English glam rock singer Bryan Ferry and his band Roxy Music, but performed in a period-appropriate 1920s jazz style. Ferry worked in the music department for the series and also appears as a singer at Moka Efti.