What is the theme in Death at La Fenice by Donna Leon?

Justice and the law is a main theme on this book. Brunetti must face a choice between doing what he believes is just and following the law that he has sworn to serve. Throughout the novel, Brunetti runs into situations involving questionable ethics and evading the law. The law is portrayed as a guideline of official policy in the novel, not without flaws, and not to be followed in the face of a conflict with one's personal ethics or morals. Brunetti decides independently, outside the law, to let Elizabeth Wellauer go unprosecuted. He manipulates the law, instead of enforcing it, so that he can follow his personal ethical and moral beliefs.