He Who Fears the Wolf by Karin Fossum

Widow Halldis Horn is murdered outside her home. The only witness is a twelve-year-old boy named Kannick who lives at a facility for boys with behavioral problems. Kannick sees escaped mental patient Errki Johrma near Halldis' house, so Errki becomes the main suspect. Meanwhile, Inspector Konrad Sejer is upset with himself for not trusting his instincts about a bank robbery that he thought was about to happen. The robber has taken a hostage and disappeared. Soon, the two cases intersect and Sejer, with his assistant Jacob Skarre, is coming up with more questions than answers about who is responsible. Fossum writes another interesting police procedural. She spends as much time on the different characters (Errki, Kannick, the bank robber) and their motivations as with Sejer and Skarre and their investigation. This is the second book in the Sejer/Skarre series. I wrote about The Indian Bride last month.