Nordic Noir
I have been on a Nordic Noir kick ever since the British Wallander debuted on the BBC, which led me to the Swedish Wallander, which I liked better, which led me to the The Girl With the Dragon Tattoo, and it just sort of went on from there. Håkan Nesser is Swedish but I think his main character, Chief Inspector Van Veeteren, is of some indeterminate northern European country, which could be Sweden or Holland or Poland, according to Wikipedia. He seems to use British police titles and ranks, which makes sense because he has lived in London for the past couple of decades. Van Veeteren is a popular character, and some of the early novels have been made into TV series in Sweden. In the first five, VV is still on the police force, and in the next five, he is retired and running an antiquarian bookshop but still getting involved in cases. He is something like a halfway mark between Sherlock Holmes and Wallander, with some of the wry and negative self-awareness that Holmes lacks and also some of the mysterious methodology, a mix of genius, showmanship and intuition, that Wallander lacks. Borkmann's Point is about a serial axe-murderer with exactly three victims, at least until he kidnaps a female police detective and no one is sure why or if he has killed her. The Point in the title is a point in time defined by Borkmann, a well-remembered mentor from VV's early days as a detective. He taught that there is always a point in the investigation where you have all the information you need to solve it, and all the information that comes in after that point will slow you down rather than help you. So if one can learn to discern that point, one can ignore all the extraneous information and just sit at ones desk and think. Unfortunately, you an only recognize Borkmann's Point after you have solved the crime, so it's more of a thought experiment than a tactic.