Law enforcement systems were introduced as the early American colonies increased in size. Prior to this, serious crime was rare and able to be handled within small communities or the family. Early policing in the United States was limited to night watchmen, constabulary and sheriffs. These were based upon the systems that were established in Europe. These individuals were usually drafted, elected or appointed to the position and were often untrained and ill-paid; they were also held in low regard by the people they served. In the 1700s, as the population grew, there was a corresponding increase in crime. In cities where the population expanded beyond 50,000 there came greater need to maintain peace and enforce laws, and effective policing was needed in order to defend the normal functioning of society.
There were several difficulties in the early days of policing. One was the question of how to balance the need for law enforcement with individual liberty. A second problem was that of law enforcement with no checks or boundaries, which had the potential to stray into the territory of vigilantism. In industry, private police forces looked after the interests of businesses. One such force, Pinkertons, protected property for the likes of railroads and livestock industries. But due to the lack of jurisdictional boundaries, it was able to employ brutal measures to break strikes. The English model of policing, with its emphasis on the rights of the individual and on crime prevention and control, was adopted in the United States. However, a trait of that system was a fractured structure of law enforcement (in 1993, it was reported that there were nearly 20,000 different law enforcement agencies within the United States). In other European countries, law enforcement was mostly centralized.
In the mid-1800s, widespread public disorder and fear of societal breakdown led to full-time police systems being established in some cities. However, the police force was plagued with political influence and corruption. Local politicians would reward their supporters with positions on the police force, and positions and promotions could be bought. Police officers often accepted bribes to overlook crimes such as drinking, gambling and prostitution. The service was further undermined by lack of training, no recruitment standards to speak of, and no job security because officers could be hired or fired at will (which resulted in high turnover of police staff.) Policing was mainly confined to foot patrols and there was no effective system of communication and little supervision. As part of their role, police were also involved in social services, such as housing the homeless or removing garbage. They often handled problems informally.
In the late 19th and early 20th century, policing changed in response to demand across America. There was a call for reform of inefficient and corrupt police agencies. In 1893, the International Association of Chiefs of Police was established. Its aim was to advance the science and art of police services through training of police professionals and encourage high professional standards. A movement known as the police professionalization movement emerged; police departments were restructured and the role of the police redefined. The movement sought to eradicate political influences in the police force and to organize law enforcement. Until the 1930s police reform was variable but in 1931, the Wickersham Commission Report (the first national study of the criminal justice system in the United States) documented police misconduct, resulting in increased focus on reform.
In the early to mid-20th century, new technologies helped transform law enforcement; the two-way radio, the patrol car and the telephone enhanced police mobility and communications. This allowed police to be more responsive, although there were also negative repercussions; police in patrol cars were removed somewhat from the community. In addition, being more easily accessible, they became involved in domestic disputes. Nowadays, modern policing employs sophisticated tactics and specialist knowledge such as police paramilitary units and special weapons and tactical (SWAT) teams.
Police forces have responded to new technologies such as the internet, and social networking may be used to survey criminal activity such as organized violence. These technologies enhance the scope of law enforcement but it is held that policing remains at its most effective when it is visible, such as the traditional beat officer. The goal remains, as ever, to make citizens feel safe and improve their quality of life.