Unlike any of the Marshal Guarnaccia mysteries that have been produced before this, this is based on a real life serial killer who was never caught. In addition there is a small story about a painting and the provenance that accumulate to a painting over a number of years and by who the attribution is made. 'There are no forgeries, only wrong attributions' states the art "expert".
The Marshal is picked for this 'team' because the 'new' Colonel doesn't want to waste one of his best men on this investigation that will come to no good end. But the Captain makes sure that the Marshal is included because he 'knows' how dogged he can be once he gets into an inquiry. The characterization is the most prominent reason for reading this book, Nabb does a great job in bringing the major characters to us as real people.