Outsider in Amsterdam by Janwillem van de Wetering
It features the police duo of Adjutant-Detective Henk Grijpstra and Detective-Sergeant Rinus de Gier. The interplay and social commentaries between and by the two almost render the plot a subordinate item. Delightful reading. For more about these two crime-fighters visit the link below.
http://en.wikipedia.org/wiki/Grijpstra_and_de_Gier