Although comparisons have been made with Wallander, I think that's mainly because it's a grown-up murder story originating in Scandinavia. It has a very different feel, and the colouring is completely different - it's glossy black where Wallander is wheat-coloured.
The plot is genuinely on a knife-edge, because both the lead characters and we the viewers are flummoxed by uncertainty. What I would particularly pick out though is the very realistic portrayal of politicians: the electoral team, their wider party, and their political allies, are portrayed like real people, with the sort of emotional maturity that political successes actually have. I think it can be difficult to frame a political plot which realistically links a small-scale intimate story with wider political issues. I can think of a lot of failures - like the Star Wars prequels or To Kill A King. This one I think works, with the political manoeuvering and the police investigation unfolding together. Very good.
ETA - I see that AMC are planning to broadcast an American remake this year. Although I tend to dislike remakes, this sounds promising.