The Fifth Woman by Henning Mankell

This murder mystery is like many of Mankell's: it has the mystery, but it also deals with the question of what the role of the police in civil society is. As in other books in this series, the murders are prompted by the murderer's sense that justice is not being done, and the victims are reprehensible. Still, Mankell (and Wallander, his detective) demonstrate a faith in justice and in the police to solve even the most carefully-planned and executed murders.