Law and the Police
To enforce his "settlement" and end the Revolution while preserving its basic changes, Napoleon created a national police system, which would be answerable directly to him through his Minister of the Interior. This system is important to understand, because it has had a great influence on law and the police ever since, not only in France but in much of Europe and parts of Latin America, Asia and Africa which were in the 1800s colonies of European countries.
To police his Empire, Napoleon created a system of regional police chiefs, known as Prefects. These Prefects, and their subordinates in each town (known as sub-delegates), were appointed by the government, not elected. These officers were chosen for their careers as young men through competitive exams and were trained at a national school. They were always assigned to a region they did not know, so they would be impartial in their application of the laws and disregard any local traditions. This system was designed to centralize all power with the national government in Paris (that is, with Napoleon).
The prefects had far greater powers than we associate with the police today; their job was not only to prevent violations of law but to monitor the population. So the police kept records on where each person lived, worked and went. The goal was to have a perfectly well-organized way of monitoring the population so that the government could know as much about the people and what they needed as possible.