Law enforcement agency

A law enforcement agency (LEA) is any government agency responsible for law enforcement within a specific jurisdiction through the employment and deployment of law enforcement officers and their resources. The most common type of law enforcement agency is the police, but various other forms exist as well, including agencies that focus on specific legal violation, or are organized and overseen by certain authorities. They typically have various powers and legal rights to allow them to perform their duties, such as the power of arrest and the use of force.

LEAs which have their ability to apply their powers restricted in some way are said to operate within a jurisdiction.

Jurisdictions are traditionally restricted to a geographic area and territory. LEA might be able to apply its powers within a state (e.g., the National Police for the entirety of France), within an administrative division (e.g., the Ontario Provincial Police for Ontario, Canada), within a division of an administrative division (e.g., the Miami-Dade Police Department for Miami-Dade County, Florida, United States), or across a collection of states typically within an international organization or political union (e.g., Europol for the European Union).

Sometimes, the jurisdiction of a law enforcement agency (LEA) is determined by the type of violation committed, the specific laws the agency enforces, the affected parties, or the severity of the offense. For example, in the United States, the Postal Inspection Service primarily investigates crimes affecting or misusing the services of the United States Postal Service, such as mail and wire fraud. If, hypothetically, a Postal Inspection Service investigation uncovered tobacco smuggling, the Bureau of Alcohol, Tobacco, Firearms and Explosives would be involved, but the Drug Enforcement Administration would not, as even though they investigate drug smuggling, their jurisdiction does not cover specifically tobacco smuggling. In other cases, an LEA's involvement is determined based on whether their involvement is requested; the Australian Federal Police, for instance, has jurisdiction over all of Australia, but usually takes on complex serious matters referred to it by another agency, and the agency^[which?] will undertake its own investigations of less serious or complex matters by consensus.

LEA jurisdictions for a country and its divisions can typically be at more than one level. The United States has five basic tiers of law enforcement jurisdiction: federal, state, county, municipality, and special jurisdiction (tribal, airport, transit, railroad, etc.). Only the municipal, county, and state levels are involved in direct policing (i.e. uniformed officers with marked cars and regular patrols), and these can still depend on each agency's role and function. As an example for the American tiers, the Chicago Police Department has jurisdiction over Chicago, but not necessarily the rest of Cook County; while the Cook County Sheriff's Office has jurisdiction over Cook County, for the most part they patrol unincorporated area and operate Cook County Jail, and leave municipalities to municipal police departments; and the rest of Illinois, primarily its state highways, are under the jurisdiction of the Illinois State Police. All three technically have overlapping jurisdictions, and though their regular duties are fairly different and they typically avoid each other's responsible areas (the Cook County Sheriff's Office typically avoids patrolling Chicago unless it is for penal or court-related duties), they are still capable of assisting each other if necessary, usually in the form of higher-tier agencies assisting lower-tier agencies.

A LEA which has a wide range of powers but whose ability is restricted geographically, typically to an area which is only part of a country, is typically referred to as local police or territorial police.

In some countries, national or federal police also participate in direct policing, although their focus and responsibilities may vary. In Brazil, there are five federal police forces with national jurisdiction—the Federal Police of Brazil, the Federal Highway Police, the Federal Railroad Police, the Federal Penal Police, and the National Public Security Force—but the Highway Police, Railroad Police, and Penal Police are restricted to specific area jurisdictions (the Brazilian Highway System, railways, and prisons respectively) and do not investigate crimes, the Federal Police performs various police duties across the country and does investigate crimes, while the National Public Security Force is a rapid reaction force deployed to assist state authorities on request.

Often, a LEA's jurisdiction will be geographically divided into operations areas for administrative and logistical efficiency reasons. An operations area is often called a command, division, or office. Colloquially, they are known as beats.