In the United States, there are a variety of different types of Law Enforcement agencies. First of all, there are municipal or city police departments. These can range in size from two or three officers in a small, rural town to close to thirty-five thousand officers in the New York City Police Department. City police departments are responsible for law enforcement activities within the city limits.
Moving out of the city into the unincorporated areas, the responsibility shifts to county police or sheriff’s departments. County police departments do not exist in every region or area. They tend to be more prevalent in larger, metropolitan areas. County police departments handle police services in the unincorporated areas and in cities that do not have their own police department.
In these counties that have a county police department, the sheriff’s department is usually limited in it’s scope of responsibility. In these areas the sheriff’s office tends to focus on serving civil papers and arrest warrants, court security, and prisoner transport. In counties, especially rural counties, that do not have a county police department, the sheriff’s office is the primary law enforcement agency for that area. They will handle all of the above mentioned responsibilities, as well as answering citizen requests for police services.
Every state also has some type of state law enforcement agency. In some states these are true state police organizations. These agencies handle large cases that might require investigation throughout the entire state. These agencies also could be called in to investigate local police agencies for corruption or use of force complaints. State police departments are also responsible for traffic enforcement on interstates and state highways.
Other states, such as Georgia, for example, have a different system. The Georgia State Patrol provides traffic enforcement throughout the state. They conduct speed enforcement, DUI enforcement, and investigate motor vehicle accidents. The Georgia Bureau of Investigation is the agency that conducts large criminal investigations that might involve multiple cities or counties. The GBI also assists small agencies in investigating serious crimes such as rapes, murders, and large drug investigations.
Federal Agencies are the next major type of law enforcement agencies. The Federal Bureau of Investigation, the Drug Enforcement Administration, and the Department of Alcohol, Tobacco, Firearms and Explosives are the three that most people are familiar with. These agencies and others are under the control of the Department of Justice.
The United States Marshals Service, the United States Customs and Border Protection, and the United States Secret Service are other agencies that are also part of the federal law enforcement system. The agencies and others are under the control of the Department of Homeland Security.
Each federal agency has a specific mission. Federal agencies are prohibited from exercising general police powers. They do enforce federal laws and work closely with local agencies on large, long-term cases. Federal law enforcement agencies are able to bring in resources that city and county agencies might not have. These multi-jurisdiction cases often bring federal, state, and local police departments together to conduct investigations that a single police agency would have difficulty handling.