Years ago, I read most of these stories.  However, this is one which escaped me.  Good to finish the lot.  These Swedish police procedureals are simply the best.  Crimes are committed.  The police are baffled, but doggedly pursue several lines of investigation.  A glimmer of an idea sets in motion the perpetrator's capture.  I like to think that the 5% of crimes that are not easily brought to justice happen in this plodding, instinctive manner.  Along the way, we are treated to small glimpses into the lives of the police force.