Tatort ("Crime Scene") is a German-language police procedural television series that has been running continuously since 1970 with 30 feature-length episodes per year, making it the longest-running German TV drama. Developed by the German public-service broadcasting organization ARD for their channel Das Erste, it is unique in its approach in that it is jointly produced by all of the organization's regional members as well as its partnering Austrian and Swiss national public-service broadcasters, whereby every regional station contributes several episodes to a common pool.
https://en.wikipedia.org/wiki/Tatort