During the political era (1840s-1930s) the functions of law enforcement were controlled by the local politicians. This era was characterized by five points--authority was coming only from politicians and the law, it was a very broad social service function, the organizational design was decentralized, law enforcement had a very intimate relationship with the community, and there was an increased usage of foot patrol. Authority from politicians posed a problem during this time. Since most of the power was given to politicians the selection of good law enforcement was not a priority. During this era law enforcement wore no type of uniform which made it difficult for citizens to recognize an officer when one was needed.
The reform era (1930s-1980s) was the second era in law enforcement. The characteristics of this era recognized the authority coming from the law and professionalism. Crime control became the primary function which made for a more centralized, efficient organization. It also provided the community with a more professional agency that used preventive patrol measures and a more rapid response to crime. During this time a managed hierarchical pyramid of control was established for police officers. When specific problems rose law enforcement created special units to take care of these issues instead of using patrol officers.
The third era of law enforcement is the community era (1980s-present). This era is characterized by the authority coming from the support of the community, law, and professionalism. A broad range of services provided a better hold on crime control in the community. Having a decentralized organization gave more authority to patrol officers and let them become more intimate with their community relationships. This era also increased the use of foot patrols and an increased knowledge of problem-solving. Law enforcement became more concerned over citizen satisfaction.