The big idea behind the show is very clear to see. To strengthen trust in the police and policemen and officers. This was certainly necessary since only a few years ago the police was completely controlled by the Nazi regime and there was no confidence in the law and criminal justice as well. Therefore, like a mantra, the diligence of the police, unusual work hours, the short sleeping time when a case has to be solved and the low pay and lack of helpful equipment are part of the voice-over or appear in a dialogue. To understand how much effort goes into solving crimes the procedures are often explained in detail.
While the national socialist past of the country made this show so important, the theme of Naziland and the WWII and all the atrocities are no theme in the show. There is no mentioning of the Jews other than a jewish sounding name. Small quips about the past in a few episodes, that is all. The past lies in the dark and no investigation goes into this direction.
Another taboo might have been the DDR, the communistic Germany behind the fence, at that time called "die Zone." It gets mentioned once in "Das zwölfte Messer" and when it happens you immediately think oh, this exists as well!
Politics in general are avoided as well, except when it justifies more financial support for the police work.
Not surprisingly, the speed and overall quality of the first episode of "Stahlnetz" was quite inconsistent. The use of dramatic musical cues whenever the date and time is mentioned appears ridiculous nowadays and spoils some rather good moments. Fortunately they refrained from doing this again in the following episodes. The audio balance changes from low to loud in a single scene depending on the distance of the actors to the only microphone they used. Once or twice when an actor turns his back to the camera you couldn't understand a word and when you turned up the volume the next moment he turned again and seemed to shout his next sentence at you.
Although there are elements you think silly or very dated it still has it's merits too. For example, the camera work was much better than you would expect from a late 50's TV series. Despite all the shortcomings the idea of showing a real" case from the police point of view and emphasizing the many departments and people involved in solving the crime gave the film a very realistic touch. The voice over works very good and holds the different police investigations together. They squeezed a lot of info into this only 35-minute long episode. The ending came very fast and no serious explanation on why this murder happened is something that I missed a lot.