Historical Roots of Policing

The first examples of policing existed in Colonial America, where informal, for-profit groups like the Night Watch attempted to discourage gambling and prostitution. In the 19th century, the US adopted the British system of policing which involved a professional, full-time, and central-organized police force. This force focused on preventing crime and preserving order. Boston was the first United States city to establish a modern police force in 1838. Commercial shipping was central to Boston’s economy, and merchant owners were concerned about cargo security. The police force was created to protect the merchant ships in the area. Shortly after, many Southern cities created police forces to catch runaway slaves and prevent revolutions. By the start of the 20^th century, most major cities had police forces that focused on preserving social control and the economy, such as protecting the workforce from labor-unions and immigrants, and preventing labor strikes. Precinct captains and sergeants were selected by local political parties, and political interests subsequently influenced police activity. 

During the 1920s, FBI Director J. Edgar Hoover set out to better police forces by creating the 1929 Wickersham Commission to investigate ineffectiveness within law enforcement. The findings of this commission led to greater separation between police forces and political parties, and increased training for new officers. Police departments began to unionize and introduced the community policing model. Community Policing strengthened the ties between law enforcement and the communities they served, placing an emphasis on forming relationships with community leaders and discussing pressing issues within their communities. This is still the most widely used policing model today.

State and Local Law Enforcement

Non-federal police departments can be broken up into four subgroups: 

1. Municipality departments, which govern cities, townships, or tribal areas, are responsible for the preservation of property, criminal investigations, and protection of life in their respective jurisdiction. 
2. Sheriffs’ departments, run by the county, perform jail operations, court-related duties, and other law enforcement activities depending on department policies, such as, serving orders of protection and transporting prisoners. 
3. State and highway police jurisdiction depends on the local legislative mandate. State officers have jurisdiction throughout their state; however, their duties depend on a state mandate. Highway officers are given specific duties to perform over highways, including traffic enforcement and/or criminal investigations. 
4. Special departments that can include universities, parks and recreation areas, and transportation facilities. Their duties vary depending on mandates, but usually include traffic enforcement and investigations. These departments often cooperate with their partner agencies.

Federal and International Law Enforcement

The United States has two main federal law enforcement departments: the Department of Justice and Department of Homeland Security. 

The Department of Justice houses a variety of agencies with different specializations.

• The U.S. Marshal Service apprehends federal fugitives, operates the Witness Protection Program, transportes federal prisoners in the judicial process, and manages seized assets that were acquired through illegal activities.
• The Drug Enforcement Agency (DEA) and the Bureau of Alcohol, Tobacco, Firearms, and Explosives enforce controlled substance regulations and laws and investigate the unlawful use, manufacture, and trafficking of alcohol, tobacco, firearms, and explosives, respectively. 
• The FBI has jurisdiction to “investigate all federal crimes that are not assigned exclusively to another federal agency.” Examples of these are threats to national security, violent crimes against interstate travelers, serial killers, white-collar crimes, and hate groups that pose a credible threat. In addition, the FBI investigates missing children, aids local law enforcement agencies upon request, and manages the Uniform Crime Reporting Program. This program centralizes crime statistics submitted by various U.S. law enforcement agencies.

The Department of Homeland Security (DHS) was created to strengthen U.S. borders and prevent attacks on U.S. soil after 9/11. It consolidated 22 federal agencies and departments, becoming the largest federal law enforcement agency. These agencies include the Federal Protective Service, Immigration and Customs Enforcement (ICE), Customs and Border Protection (CBP), and the Secret Service.

• The Federal Protective Service is tasked with protecting critical infrastructures of the U.S. government and investigating any criminal activity against these locations. 
• ICE and CBP are similar since both operate at the border and are tasked with deterring and investigating cross-border criminal activity. 
• The Secret Service protects the President and Vice President, their families, and foreign visitors of importance. They are also in charge of investigating threats to United States financial organizations. These include credit card fraud, ransomware, and computer network breaches. The Secret Service also offers forensics assistance to the National Center for Missing and Exploited Children.

Finally, when crime is committed in more than one country, the International Police Organization (INTERPOL) aids and connects the participating law enforcement agencies. INTERPOL was created in 1914 as world leaders sought a more integrated way to solve crimes across countries. The organization consists of 194 countries who share intelligence, forensics services, and assistance to fellow countries. Its main mission is to combat terrorism, cyber-crime, and organized crime, which are the gravest threats to international security. Its jurisdiction is created through mutual agreement with the member countries.