There are 5 defined eras of law enforcement. This is the first of the five (5) eras. We will take a look back at the evolution of law enforcement and how our current day law enforcement has been influenced by hundreds of thousands of years of people trying to control crime, offenses and human behavior not acceptable in their communities. Early history set a template for how our modern day law enforcement functions. We use many of the terms, titles and ideas that were developed long before America was even a nation.