Arne Dahl's "Bad Blood"... part of his Intercrime police series some of which were televised and shown on UK TV last year as "Arne Dahl".
Originally published in Sweden in 1998... the story and the writing ages well. In "Bad Blood" an American serial killer comes to Sweden and Hjelm and his team must track the killer down before any more signature gruesome deaths occur. The hunt takes the individual members of the police team into the dark stories of killer and victims alike. It also takes Hjelm and Holm to the USA to work with the FBI team who originally tracked the Kentucky Killer, the name given to this sadistic killer. It is a disturbing tale with political undertones but a surprising warmth and wit in the characters of the police team... more than shown in the telly series, I think.
A definite recommend to read the books that gave rise to this series if this is anything to go by. You can read a couple of reviews over on Euro Crime here.