The Snowman by Jo Nesbo

A boy awakes to find his mother gone and a snowman outside wearing her scarf. Inspector Harry Hole and his colleagues are called to the home and slowly realize that the case and clues are similar to other cases of mothers who have disappeared. Harry is also troubled by the fact that he's received a letter from the perpetrator, whom the Oslo police nickname "the Snowman." Soon, one of the women is found brutally murdered and Harry realizes that they are on the trail of a serial killer. With Harry being the only Norwegian policeman to have received serial killer training in the U.S., he's the perfect person to catch him. The Snowman is the seventh book in the Harry Hole series, but only the fourth to be published in the U.S. It will be released next month.