The Leopard by Jo Nesbo

Inspector Harry Hole is reluctantly persuaded to come home to Oslo from a self-imposed exile in Hong Kong to aid in the case of a suspected serial killer. Two women have been murdered in a similar way and Harry's expertise is invaluable. Kripos, the NCIS, is officially running the investigation, so Harry and his two colleagues have to keep their actions secret. In addition, Harry's father is dying and he's developed a fondness for opium while on his sojourn. As he tussles with Mikael Bellman from Kripos and more bodies pile up, Harry tries to find a connection between the victims while struggling with the chaos in his personal life. The Leopard is the eighth book in the Harry Hole series and is much too long. It suffers from plot twist after plot twist, diluting the mystery. The Redeemer and The Snowman are better books.