@Edent One thing you missed is the connection to Tatort (https://en.wikipedia.org/wiki/Tatort) and Polizeiruf 110 (https://en.wikipedia.org/wiki/Polizeiruf_110). In two of the Tatortreiniger episodes, Schotty meets the investigation team of one of the Polizeiruf 110 crews. Also his phone's ringtone is a reference to the Tatort title theme. There's probably more connections I'm forgetting now. Tatort - Wikipedia