The original inspiration for this book came from scholars such as James Richardson, Roger Lane, Wilbur Miller, Alan Williams, Eric Monkkonen, and the many other historians who have studied the police in countries other than Italy. Despite their variety of approaches, all of these authors have recognized the police as a key institution of the modern age, and one that can be tied to a host of historical concerns, including the growth of urban bureaucracy, changing perceptions of crime, shifting class relations, and the evolution of new forms of political power. As a distinct institution, the centralized police is a relatively recent phenomenon, and its advent on the European continent in the eighteenth century and throughout the rest of the western world during the nineteenth century marked a fundamental departure from traditional modes of administration. Both obvious and ubiquitous, the police symbolized a new personalized presence of the government in people's everyday affairs, and it remained to each culture to determine the nature and limits of that presence. Historians have thus come to realize that the method by which a society enforces its laws is often as revealing as the laws themselves.

In Italy, however, police history has not fared well. Until very recently, it has been confined to abstract juridical discussions of the law, which seldom touch ground, and “alternative” diatribes, which seek to expose the police as a nefarious instrument of class warfare.