I agree with the other reviewers, the problem with the series is the script. It reminds me of some bad American police procedurals. In general I have no problem with the cast. Episodes 1-3 were better than episodes 4 & 5.
Hanna is a stereotype of a green detective who goes off on her own and doesn't take orders from her senior partner. She's immature, she can't set professional boundaries which drives her to go it alone to "save the victim". In real life she would have likely flunked as a detective. She goes off without regard to her safety and that of others. It's related to another stereotypical character that writers love, the rogue cop.
I'm a big fan of the "Beck" series set in Stockholm that has a really good cast and superior scripts. This series isn't anywhere near "Beck" in quality, the scripts need a lot of work.
I'm a fan of "Sandhamn Murders" also from Viveca Sten mystery novels. Different cast, writers and different production companies, "Are Murders" isn't the same caliber..