Policing in the United States
Encyclopedia
Law enforcement in the United States is one of three major components of the criminal justice
Criminal justice
Criminal Justice is the system of practices and institutions of governments directed at upholding social control, deterring and mitigating crime, or sanctioning those who violate laws with criminal penalties and rehabilitation efforts...

 system of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, along with courts and corrections
Corrections
In criminal justice, particularly in North America, correction, corrections, and correctional, are umbrella terms describing a variety of functions typically carried out by government agencies and involving the punishment, treatment, and supervision of persons who have been convicted of crimes....

. Although there exists an inherent interrelatedness between the different groups that make up the criminal justice system based on their crime deterrence purpose, each component operates independently from one another. However, the judiciary is vested with the power to make legal determinations regarding the conduct of the other two components.

Apart from maintaining order and service functions, the purpose of policing is the investigation of suspected criminal activity and the referral of the results of investigations and of suspected criminals to the courts. Law enforcement, to varying degrees at different levels of government and in different agencies, is also commonly charged with the responsibilities of deterring criminal activity and of preventing the successful commission of crimes in progress; the service and enforcement of warrants
Warrant (law)
Most often, the term warrant refers to a specific type of authorization; a writ issued by a competent officer, usually a judge or magistrate, which permits an otherwise illegal act that would violate individual rights and affords the person executing the writ protection from damages if the act is...

, writ
Writ
In common law, a writ is a formal written order issued by a body with administrative or judicial jurisdiction; in modern usage, this body is generally a court...

s and other orders of the courts.

Law enforcement agencies are also involved in providing first response to emergencies and other threats to public safety
Public Safety
Public safety involves the prevention of and protection from events that could endanger the safety of the general public from significant danger, injury/harm, or damage, such as crimes or disasters .-See also:* By nation...

; the protection of certain public facilities and infrastructure
Infrastructure
Infrastructure is basic physical and organizational structures needed for the operation of a society or enterprise, or the services and facilities necessary for an economy to function...

; the maintenance of public order; the protection of public officials; and the operation of some correctional facilities (usually at the local level).

History

In 1626, the New York City Sheriff's Office
New York City Sheriff's Office
The New York City Sheriff's Office is the civil law enforcement division of the New York City Department of Finance. The Sheriff's office is headed by a sheriff, who is appointed to the position by the mayor, unlike most sheriffs in New York State who are elected officials...

 was founded. In 1635, the Town of Boston started its first "Night Watch
Night Watch
A Night Watch is a lookout, guard or patrol at night, in a nautical, military or police context; see Watchman .Night Watch or Nightwatch as a proper name may refer to:-Art:...

". The first local modern police department established in the United States was the Boston Police Department
Boston Police Department
The Boston Police Department , created in 1838, holds the primary responsibility for law enforcement and investigation within the city of Boston, Massachusetts. It is one of the oldest police departments in the United States...

 in 1838, followed by the New York City Police Department
New York City Police Department
The New York City Police Department , established in 1845, is currently the largest municipal police force in the United States, with primary responsibilities in law enforcement and investigation within the five boroughs of New York City...

 in 1845. Early on, police were not respected by the community, as corruption
Police corruption
Police corruption is a specific form of police misconduct designed to obtain financial benefits, other personal gain, or career advancement for a police officer or officers in exchange for not pursuing, or selectively pursuing, an investigation or arrest....

 was rampant. In the late 19th and early 20th century, there were few specialized units in police departments.

The advent of the police car, two-way radio
Two-way radio
A two-way radio is a radio that can both transmit and receive , unlike a broadcast receiver which only receives content. The term refers to a personal radio transceiver that allows the operator to have a two-way conversation with other similar radios operating on the same radio frequency...

, and telephone in the early 20th century transformed policing into a reactive strategy that focused on responding to calls for service
Calls for service
Calls for service generally refers to assignments that are typically distributed to public safety professionals that require their presence to resolve, correct or assist a particular situation...

. In the 1920s, led by Berkeley, California
Berkeley, California
Berkeley is a city on the east shore of the San Francisco Bay in Northern California, United States. Its neighbors to the south are the cities of Oakland and Emeryville. To the north is the city of Albany and the unincorporated community of Kensington...

 police chief, August Vollmer
August Vollmer
August "Gus" Vollmer was a leading figure in the development of the field of criminal justice in the United States in the early 20th century. He was also the first police chief of Berkeley, California.-Youth:...

, police began to professionalize, adopt new technologies, and place emphasis on training. With this transformation, police command and control became more centralized.

O.W. Wilson
Orlando Winfield Wilson
Orlando Winfield Wilson , also known as O.W. Wilson, was an influential leader in policing, having served as Superintendent of Police of the Chicago Police Department, chief of police in Fullerton, California and Wichita, Kansas, and authored several books on policing.-Background:Wilson was born on...

, a student of Vollmer, helped reduce corruption
Police corruption
Police corruption is a specific form of police misconduct designed to obtain financial benefits, other personal gain, or career advancement for a police officer or officers in exchange for not pursuing, or selectively pursuing, an investigation or arrest....

 and introduce professionalism in Wichita, Kansas
Wichita, Kansas
Wichita is the largest city in the U.S. state of Kansas.As of the 2010 census, the city population was 382,368. Located in south-central Kansas on the Arkansas River, Wichita is the county seat of Sedgwick County and the principal city of the Wichita metropolitan area...

, and later in the Chicago Police Department
Chicago Police Department
The Chicago Police Department, also known as the CPD, is the principal law enforcement agency of Chicago, Illinois, in the United States, under the jurisdiction of the Mayor of Chicago. It is the largest police department in the Midwest and the second largest local law enforcement agency in the...

. Strategies employed by O.W. Wilson included rotating officers from community to community to reduce their vulnerability to corruption, establishing of a non-partisan police board to help govern the police force, a strict merit system for promotions within the department, and an aggressive, recruiting drive with higher police salaries to attract professionally qualified officers. Despite such reforms, police agencies were led by highly autocratic leaders, and there remained a lack of respect between police and minority communities. During the professionalism era of policing, law enforcement agencies concentrated on dealing with felonies
Felony
A felony is a serious crime in the common law countries. The term originates from English common law where felonies were originally crimes which involved the confiscation of a convicted person's land and goods; other crimes were called misdemeanors...

 and other serious crime.

Following urban unrest in the 1960s, police placed more emphasis on community relations, and enacted reforms such as increased diversity in hiring. The Kansas City Preventive Patrol study
Kansas City preventive patrol experiment
The Kansas City preventive patrol experiment was a landmark experiment carried out between 1972 and 1973 by the Kansas city police department of Kansas City, Missouri. It was evaluated by the Police Foundation. It was designed to test the assumption that the presence of police officers in marked...

 in the 1970s found the reactive approach to policing to be ineffective. In the 1990s, many law enforcement agencies began to adopt community policing strategies, and others adopted problem-oriented policing
Problem-oriented policing
Problem-oriented policing is an approach to policing in which discrete pieces of police business are subject to microscopic examination in hopes that...

. In the 1990s, CompStat
CompStat
CompStat—or COMPSTAT— is the name given to the New York City Police Department's accountability process and has since been replicated in many other departments...

 was developed by the New York Police Department as an information-based system for tracking and mapping
Crime mapping
Crime mapping is used by analysts in law enforcement agencies to map, visualize, and analyze crime incident patterns. It is a key component of crime analysis and the CompStat policing strategy...

 crime patterns and trends, and holding police accountable for dealing with crime problems. CompStat, and other forms of information-led policing, have since been replicated in police departments across the United States and around the world.

In 1905, the Pennsylvania State Police
Pennsylvania State Police
The Pennsylvania State Police is the state police force of Pennsylvania, responsible for statewide law enforcement. It was founded in 1905 by order of Governor Samuel Pennypacker, in response to the private police forces used by mine and mill owners to stop worker strikes and the inability or...

 became the first state police
State police
State police are a type of sub-national territorial police force, particularly in Australia and the United States. Some other countries have analogous police forces, such as the provincial police in some Canadian provinces, while in other places, the same responsibilities are held by national...

 agency established, as recommended by Theodore Roosevelt
Theodore Roosevelt
Theodore "Teddy" Roosevelt was the 26th President of the United States . He is noted for his exuberant personality, range of interests and achievements, and his leadership of the Progressive Movement, as well as his "cowboy" persona and robust masculinity...

's Anthracite Strike Commission and Governor Samuel Pennypacker. See also Coal Strike of 1902
Coal Strike of 1902
The Coal Strike of 1902 was a strike by the United Mine Workers of America in the anthracite coal fields of eastern Pennsylvania. Miners were on strike asking for higher wages, shorter workdays, and the recognition of their union...

.

California municipalities were among the first to hire women and minorities as officers. The first female police officer was Alice Stebbins Wells, who was hired by the Los Angeles Police Department
Los Angeles Police Department
The Los Angeles Police Department is the police department of the city of Los Angeles, California. With just under 10,000 officers and more than 3,000 civilian staff, covering an area of with a population of more than 4.1 million people, it is the third largest local law enforcement agency in...

 in 1910. The LAPD also hired its first two African American police officers, Robert William Stewart and Roy Green, in 1886. The first female deputy sheriff, Margaret Q. Adams
Margaret Q. Adams
Margaret Queen Adams , née Margaret Queen Phillips, became the first woman deputy sheriff in the United States in 1912...

, was hired by the Los Angeles County Sheriff's Department
Los Angeles County Sheriff's Department
The Los Angeles County Sheriff's Department is a local county law enforcement agency that serves Los Angeles County, California. It is the fourth largest local policing agency in the United States, with the New York City Police Department being the first. The second largest is the Chicago Police...

 in 1912.

Types of police

Policing in the United States is conducted by numerous types of agency at many different levels. Every state has their own nomenclature for agencies, and their powers, responsibilities and funding varies from state to state.

Federal

Federal police possess full federal authority as given to them under United States Code
United States Code
The Code of Laws of the United States of America is a compilation and codification of the general and permanent federal laws of the United States...

 (U.S.C.). Federal Law Enforcement Officers are authorized to enforce various laws at the federal level.
Both types operate at the highest level and are endowed with police roles, both may maintain a small component of the other (for example, the FBI Police
Federal Bureau of Investigation Police
The Federal Bureau of Investigation Police are the uniformed division of the FBI who are tasked to protect FBI facilities, properties, personnel, users, visitors and operations from harm and may enforce certain laws and administrative regulations....

). The agencies have nationwide jurisdiction for enforcement of federal law. All federal agencies are limited by the U.S. Code to investigating only matters that are explicitly within the power of the federal government. However, federal investigative powers have become very broad in practice, especially since the passage of the USA PATRIOT Act
USA PATRIOT Act
The USA PATRIOT Act is an Act of the U.S. Congress that was signed into law by President George W. Bush on October 26, 2001...

.

The Department of Justice
United States Department of Justice
The United States Department of Justice , is the United States federal executive department responsible for the enforcement of the law and administration of justice, equivalent to the justice or interior ministries of other countries.The Department is led by the Attorney General, who is nominated...

 (DOJ) is responsible for most law enforcement duties at the federal level. It includes the Federal Bureau of Investigation
Federal Bureau of Investigation
The Federal Bureau of Investigation is an agency of the United States Department of Justice that serves as both a federal criminal investigative body and an internal intelligence agency . The FBI has investigative jurisdiction over violations of more than 200 categories of federal crime...

 (FBI), the Drug Enforcement Administration
Drug Enforcement Administration
The Drug Enforcement Administration is a federal law enforcement agency under the United States Department of Justice, tasked with combating drug smuggling and use within the United States...

 (DEA), the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF), the United States Marshals Service
United States Marshals Service
The United States Marshals Service is a United States federal law enforcement agency within the United States Department of Justice . The office of U.S. Marshal is the oldest federal law enforcement office in the United States; it was created by the Judiciary Act of 1789...

, the Federal Bureau of Prisons
Federal Bureau of Prisons
The Federal Bureau of Prisons is a federal law enforcement agency subdivision of the United States Department of Justice and is responsible for the administration of the federal prison system. The system also handles prisoners who committed acts considered felonies under the District of Columbia's...

 (BOP) and others.

The Department of Homeland Security
United States Department of Homeland Security
The United States Department of Homeland Security is a cabinet department of the United States federal government, created in response to the September 11 attacks, and with the primary responsibilities of protecting the territory of the United States and protectorates from and responding to...

 (DHS) is another branch with numerous federal law enforcement agencies reporting to it. U.S. Customs and Border Protection
U.S. Customs and Border Protection
U.S. Customs and Border Protection is a federal law enforcement agency of the United States Department of Homeland Security charged with regulating and facilitating international trade, collecting import duties, and enforcing U.S. regulations, including trade, customs and immigration. CBP is the...

 (CBP), U.S. Immigration and Customs Enforcement
U.S. Immigration and Customs Enforcement
U.S. Immigration and Customs Enforcement is a federal law enforcement agency under the United States Department of Homeland Security , responsible for identifying, investigating, and dismantling vulnerabilities regarding the nation's border, economic, transportation, and infrastructure security...

 (ICE), United States Secret Service
United States Secret Service
The United States Secret Service is a United States federal law enforcement agency that is part of the United States Department of Homeland Security. The sworn members are divided among the Special Agents and the Uniformed Division. Until March 1, 2003, the Service was part of the United States...

 (USSS), United States Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...

 (USCG), and the Transportation Security Administration
Transportation Security Administration
The Transportation Security Administration is an agency of the U.S. Department of Homeland Security that exercises authority over the safety and security of the traveling public in the United States....

 (TSA) are some of the agencies that report to DHS
United States Department of Homeland Security
The United States Department of Homeland Security is a cabinet department of the United States federal government, created in response to the September 11 attacks, and with the primary responsibilities of protecting the territory of the United States and protectorates from and responding to...

.

At a crime or disaster scene affecting large numbers of people, multiple jurisdictions, or broad geographic areas, many police agencies may be involved by mutual aid
Mutual aid (emergency services)
In emergency services, mutual aid is an agreement among emergency responders to lend assistance across jurisdictional boundaries. This may occur due to an emergency response that exceeds local resources, such as a disaster or a multiple-alarm fire. Mutual aid may be ad hoc, requested only when...

 agreements, for example the United States Federal Protective Service
United States Federal Protective Service
The Federal Protective Service is the federal police force of the Secretary of Homeland Security. As a component of U.S. Department of Homeland Security, National Protection and Programs Directorate within DHS Headquarters, FPS is responsible for law enforcement and security of nearly 9,000...

 responded to the Hurricane Katrina
Hurricane Katrina
Hurricane Katrina of the 2005 Atlantic hurricane season was a powerful Atlantic hurricane. It is the costliest natural disaster, as well as one of the five deadliest hurricanes, in the history of the United States. Among recorded Atlantic hurricanes, it was the sixth strongest overall...

 natural disaster. Command in such situations remains a complex and flexible issue.

The federal government is prohibited from exercising general police powers due to restrictions in the constitution, because the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 is organized as a union of sovereign states, which each retain their police, military and domestic law-making powers. For example, the State's National Guard is the state's military. The constitution gives the federal government the power to deal with foreign affairs and interstate affairs (affairs between the states). For policing, this means that if a non-federal crime is committed in a state and the fugitive does not flee the state, the federal government has no jurisdiction. However, once the fugitive crosses a state line he or she violates the federal law of interstate flight and is subject to federal jurisdiction, at which time federal law enforcement agencies may become involved.

State

Most all states operate statewide government agencies that provide law enforcement duties, including investigation
Criminal procedure
Criminal procedure refers to the legal process for adjudicating claims that someone has violated criminal law.-Basic rights:Currently, in many countries with a democratic system and the rule of law, criminal procedure puts the burden of proof on the prosecution – that is, it is up to the...

s and state patrols. They may be called State Police
State police
State police are a type of sub-national territorial police force, particularly in Australia and the United States. Some other countries have analogous police forces, such as the provincial police in some Canadian provinces, while in other places, the same responsibilities are held by national...

, State Patrol or Highway Patrol
Highway patrol
A highway patrol is either a police unit created primarily for the purpose of overseeing and enforcing traffic safety compliance on roads and highways, or a detail within an existing local or regional police agency that is primarily concerned with such duties.Duties of highway patrols or traffic...

, and are normally part of the state Department of Public Safety
Department of Public Safety
The Department of Public Safety , also called an Office of Public Safety, is a state or local government umbrella agency in the United States which serves to assist the certain agencies in their services by providing administrative, financial, and technical services and support for core public...

. In addition, the Attorney General
State Attorney General
The state attorney general in each of the 50 U.S. states and territories is the chief legal advisor to the state government and the state's chief law enforcement officer. In some states, the attorney general serves as the head of a state department of justice, with responsibilities similar to those...

's office of each state has their own state bureaus of investigation
State bureau of investigation
A State Bureau of Investigation is a state-level detective agency in the United States. They are plainclothes agencies which usually investigate both criminal and civil cases involving the state and/or multiple jurisdictions...

. In Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 the Texas Ranger Division
Texas Ranger Division
The Texas Ranger Division, commonly called the Texas Rangers, is a law enforcement agency with statewide jurisdiction in Texas, and is based in Austin, Texas...

 fulfill this role though they have their history in the period before Texas became a state.

Various departments of State Governments may have their own enforcement division such as capitol police
Capitol police
Capitol police in the United States are agencies charged with the provision of security police services for various state agencies, but especially State Legislatures. Capitol police may function as part of the state police or may be an independent agency...

, Campus Police
Campus police
Campus Police or University police in the United States and Canada are often sworn police officers employed by a public school district, college or university to protect the campus and surrounding areas and the people who live on, work on and visit it....

, State Hospitals
Psychiatric hospital
Psychiatric hospitals, also known as mental hospitals, are hospitals specializing in the treatment of serious mental disorders. Psychiatric hospitals vary widely in their size and grading. Some hospitals may specialise only in short-term or outpatient therapy for low-risk patients...

, Departments of Correction
Department of Corrections
A Department of Corrections is a governmental agency responsible for overseeing the incarceration of persons convicted of crimes within a particular jurisdiction. Entities serving that purpose include:* Department of Corrections...

, Water police
Water police
Water police, also called harbour patrols, port police, marine/maritime police, nautical patrols, bay constables or river police, are police officers, usually a department of a larger police organisation, who patrol in water craft...

, environmental (fish and game/wildlife) Game Wardens or Conservation Officers (who have full police powers and statewide jurisdiction). In Colorado, for instance, the Department of Revenue has its own investigative branch, as do many of the state funded universities.

County

Also known as parishes and boroughs, county law enforcement is provided by Sheriffs' Departments or Offices and County police.

County police

County police tend to exist only in metropolitan counties and have countywide jurisdiction. In some areas, there is a sheriff
Sheriff
A sheriff is in principle a legal official with responsibility for a county. In practice, the specific combination of legal, political, and ceremonial duties of a sheriff varies greatly from country to country....

's department which only handles minor issues such as service of papers such as a constable
Constable
A constable is a person holding a particular office, most commonly in law enforcement. The office of constable can vary significantly in different jurisdictions.-Etymology:...

 in other areas, along with security for the local courthouse. In other areas, there are no county police and the local sheriff is the exclusive law enforcement agency and acts as both sheriff and county police, which is much more common than there being a separate county police force. County police tend to fall into three broad categories:
  • Full-service - provide the full spectrum of police services to the entire county, irrespective of local communities, and may provide contractual security police
    Security police
    In some countries, including the United States, security police are those persons, employed by or for a governmental agency, who provide police and security services to those agencies' properties....

     services to special districts within the county.
    • Hawaii - Hawaii has only county police, there are no local police.
  • Limited service - provide services to unincorporated areas of the county (and may provide services to some incorporated areas by contract), and usually provide contractual security police services to special districts within the county.
  • Restricted service - provide security police
    Security police
    In some countries, including the United States, security police are those persons, employed by or for a governmental agency, who provide police and security services to those agencies' properties....

     to county owned and operated facilities and parks. Some may also perform some road patrol duties on county built and maintained roads, and provide support to municipal police departments in the county. Some northeastern
    Northeastern United States
    The Northeastern United States is a region of the United States as defined by the United States Census Bureau.-Composition:The region comprises nine states: the New England states of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont; and the Mid-Atlantic states of New...

     states maintain county detectives in their county attorney
    County attorney
    A county attorney in many areas of the United States is the chief legal officer for a county or local judicial district. It is usually an elected position...

    s' offices.

Sheriffs' offices

  • Full service - The most common type, provide all traditional law-enforcement functions, including countywide patrol and investigations irrespective of municipal boundaries.
  • Limited service - along with the above, perform some type of traditional law-enforcement function such as investigations and patrol. This may be limited to security police
    Security police
    In some countries, including the United States, security police are those persons, employed by or for a governmental agency, who provide police and security services to those agencies' properties....

     duties on county properties (and others by contract) to the performance of these duties in unincorporated areas of the county, and some incorporated areas by contract.
  • Restricted service - provide basic court related services such as keeping the county jail, transporting prison
    Prison
    A prison is a place in which people are physically confined and, usually, deprived of a range of personal freedoms. Imprisonment or incarceration is a legal penalty that may be imposed by the state for the commission of a crime...

    ers, providing courthouse
    Courthouse
    A courthouse is a building that is home to a local court of law and often the regional county government as well, although this is not the case in some larger cities. The term is common in North America. In most other English speaking countries, buildings which house courts of law are simply...

     security and other duties with regard to service of process
    Service of process
    Service of process is the procedure employed to give legal notice to a person of a court or administrative body's exercise of its jurisdiction over that person so as to enable that person to respond to the proceeding before the court, body or other tribunal...

     and summons
    Summons
    Legally, a summons is a legal document issued by a court or by an administrative agency of government for various purposes.-Judicial summons:...

    es that are issued by county and state court
    Court
    A court is a form of tribunal, often a governmental institution, with the authority to adjudicate legal disputes between parties and carry out the administration of justice in civil, criminal, and administrative matters in accordance with the rule of law...

    s. The sheriff also often conducts auction
    Auction
    An auction is a process of buying and selling goods or services by offering them up for bid, taking bids, and then selling the item to the highest bidder...

     sales of real property
    Real property
    In English Common Law, real property, real estate, realty, or immovable property is any subset of land that has been legally defined and the improvements to it made by human efforts: any buildings, machinery, wells, dams, ponds, mines, canals, roads, various property rights, and so forth...

     in foreclosure
    Foreclosure
    Foreclosure is the legal process by which a mortgage lender , or other lien holder, obtains a termination of a mortgage borrower 's equitable right of redemption, either by court order or by operation of law...

     in many jurisdictions, and is often also empowered to conduct seizures of chattel property to satisfy a judgment. In other jurisdictions, these civil process duties are performed by other officers, such as a marshal
    Marshal
    Marshal , is a word used in several official titles of various branches of society. The word is an ancient loan word from Old French, cf...

     or constable
    Constable
    A constable is a person holding a particular office, most commonly in law enforcement. The office of constable can vary significantly in different jurisdictions.-Etymology:...

    .

Municipal

See Municipal police departments of the United States for a list


Municipal police
Municipal police
.Municipal police are law enforcement agencies that are under the control of local government, including the municipal government, where it is the smallest administrative subdivision. They receive pay from the city budget, and usually have fewer rights than the "state paid" police...

 range from one-officer agencies (sometimes still called the town marshal) to the 40,000 men and women of the New York City Police Department
New York City Police Department
The New York City Police Department , established in 1845, is currently the largest municipal police force in the United States, with primary responsibilities in law enforcement and investigation within the five boroughs of New York City...

. Most municipal agencies take the form (Municipality Name) Police Department. Many individual cities and towns will have their own police department, with larger communities typically having larger departments with greater budgets, resources, and responsibilities.

Metropolitan departments, such as the Las Vegas Metropolitan Police Department
Las Vegas Metropolitan Police Department
The Las Vegas Metropolitan Police Department is a joint city-county police force for the City of Las Vegas and Clark County, Nevada. It is run by the Sheriff of Clark County, elected every four years. The current Sheriff of Clark County is Douglas C...

, have jurisdiction covering multiple communities and municipalities, often over a wide area typically coterminous with one or more cities or counties. Metropolitan departments have usually have been formed by a merger between local agencies, typically several local police departments and often the local sheriff's department or office, in efforts to provide greater efficiency by centralizing command and resources and to resolve jurisdictional problems, often in communities experiencing rapid population growth and urban sprawl
Urban sprawl
Urban sprawl, also known as suburban sprawl, is a multifaceted concept, which includes the spreading outwards of a city and its suburbs to its outskirts to low-density and auto-dependent development on rural land, high segregation of uses Urban sprawl, also known as suburban sprawl, is a...

, or in neighboring communities too small to afford individual police departments. Some county sheriff's departments, such as the Los Angeles County Sheriff's Department
Los Angeles County Sheriff's Department
The Los Angeles County Sheriff's Department is a local county law enforcement agency that serves Los Angeles County, California. It is the fourth largest local policing agency in the United States, with the New York City Police Department being the first. The second largest is the Chicago Police...

, are contracted to provide full police services to local cities within their counties.

Other

U.S. Territories - Commonwealth of Puerto Rico - Puerto Rico State Police Puerto Rico Police Department

It traces back to 1837, when Spanish governor Francisco Javier de Moreda y Prieto created La Guardia Civil de Puerto Rico (Puerto Rico Civil Guard) to protect the lives and property of Puerto Ricans who at the time were Spanish subjects, and provide police services to the entire island, even though many municipalities maintain their own police force. The United States invaded and took possession of Puerto Rico in July 1898 as a result of the Spanish American War and has controlled the island as a US territory since then. The Insular Police of Porto Rico was created on February 21, 1899, under the command of Col. Frank Thacher (US Marine officer during the Spanish American War), with an authorized strength of 313 sworn officers. As of 2009, the PRPD has over 17,292 officers.
See Specialist police departments of the United States for a list

There are other types of specialist police department with varying jurisdictions. Most of these serve special-purpose district
Special-purpose district
Special-purpose districts or special district governments in the United States are independent governmental units that exist separately from, and with substantial administrative and fiscal independence from, general purpose local governments such as county, municipal, and township governments. As...

s and are Special district police. In some states, they serve as little more than security police
Security police
In some countries, including the United States, security police are those persons, employed by or for a governmental agency, who provide police and security services to those agencies' properties....

, but in states such as California, special district forces are composed of fully sworn peace officers with statewide authority.

These agencies can be transit police
Transit police
Transit police are a specialized police agency or unit employed by a common carrier, which could be a transit district, railroad, bus line, other transport carrier, or the state...

, school district police, campus police
Campus police
Campus Police or University police in the United States and Canada are often sworn police officers employed by a public school district, college or university to protect the campus and surrounding areas and the people who live on, work on and visit it....

, airport police
Airport police
Airport Police units are a security police agency assigned to perform law enforcement functions at airports. In some cases, they are branches of larger general purposes agencies. Other variations include dedicated agencies, combined police/fire agencies and even military units...

, park police
Park police
Park police are a type of security police who function as a full service law enforcement agency with responsibilities and jurisdiction in park areas primarily located in cities and other urban areas...

 or police departments responsible for protecting government property such as the Los Angeles General Services Police
Los Angeles General Services Police
The Los Angeles General Services Police is a law enforcement agency providing security police and security guard services to the Los Angeles City Hall, the Los Angeles Central Library, the Los Angeles Zoo, and the city's parks, having similar duties of the late Los Angeles County Office of Public...

. Some agencies, such as the Port Authority of New York and New Jersey Police Department, have multi-state powers. There are also some private (non-governmental) agencies, such as the Co-op City Department of Public Safety
Co-op City Department of Public Safety
The Co-op City Department of Public Safety is a security police force in the Bronx borough of New York City whose duties are to protect the property and citizens of Co-op City, and to enforce state and city laws on Co-op City property...

.

Police functions

Textbooks and scholars have identified three primary police agency functions. The following is cited from The American System of Criminal Justice, by George F. Cole and Christopher E. Smith, 2004, 10th edition, Wadsworth/Thomson Learning:
  • Order maintenance. This is the broad mandate to keep the peace or otherwise prevent behaviors which might disturb others. This can deal with things ranging from a barking dog to a fist-fight. By way of description, Cole and Smith note that police are usually called-on to "handle" these situations with discretion, rather than deal with them as strict violations of law, though of course their authority to deal with these situations are based in violations of law.

  • Law enforcement. Those powers are typically used only in cases where the law has been violated and a suspect must be identified and apprehended. Most obvious instances include robbery
    Robbery
    Robbery is the crime of taking or attempting to take something of value by force or threat of force or by putting the victim in fear. At common law, robbery is defined as taking the property of another, with the intent to permanently deprive the person of that property, by means of force or fear....

    , murder
    Murder
    Murder is the unlawful killing, with malice aforethought, of another human being, and generally this state of mind distinguishes murder from other forms of unlawful homicide...

    , or burglary
    Burglary
    Burglary is a crime, the essence of which is illicit entry into a building for the purposes of committing an offense. Usually that offense will be theft, but most jurisdictions specify others which fall within the ambit of burglary...

    . This is the popular notion of the main police function, but the frequency of such activity is dependent on geography and season.

  • Service. Services may include rendering first aid
    First aid
    First aid is the provision of initial care for an illness or injury. It is usually performed by non-expert, but trained personnel to a sick or injured person until definitive medical treatment can be accessed. Certain self-limiting illnesses or minor injuries may not require further medical care...

    , providing tourist information, guiding the disoriented, or acting as educators (on topics such as preventing drug use
    Drug abuse
    Substance abuse, also known as drug abuse, refers to a maladaptive pattern of use of a substance that is not considered dependent. The term "drug abuse" does not exclude dependency, but is otherwise used in a similar manner in nonmedical contexts...

    ). Cole and Smith cited one study which showed 80% of all calls for police assistance did not involve crimes, but this may not be the case in all parts of the country. Because police agencies are traditionally available year-round, 24 hours a day, citizens call upon police departments not only in times of trouble, but also when just inconvenienced. As a result, police services may include roadside auto assistance, providing referrals to other agencies, finding lost pets or property, or checking locks on vacationers' homes.

Styles of Policing

Given the broad mandates of police work, and yet having limited resources, police administrators must develop policies to prioritize and focus their activities. Some of the more controversial policies restrict, or even forbid, high-speed vehicular pursuits.

Three styles of policing develop from a jurisdiction’s socioeconomic characteristics, government organization, and choice of police administrators. According to a study by James Q. Wilson (”Varieties of Police Behavior”, 1968, 1978, Harvard University Press), there were three distinct types of policing developed in his study of eight communities. Each style emphasized different police functions, and were linked to specific characteristics of the community the department served. (Wilson’s field of study was in the United States, and it is not clear if similar studies have been done for other countries with different governmental organization and laws.)
  • Watchman. Emphasizes maintaining order, usually found in communities with a declining industrial base, and a blue-collar, mixed ethnic/racial population. This form of policing is implicitly less pro-active than other styles, and certain offenses may be “overlooked” on a variety of social, legal, and cultural grounds, as long as the public order is maintained. Smith and Cole comment the broad discretion exercised in this style of policing can result in charges of discrimination, when it appears police treatment of different groups results in the perception that some groups get better treatment than others;

  • Legalistic. Emphasizes law enforcement and professionalism. This is usually found in reform-minded cities, with mixed socioeconomic composition. Officers are expected to generate a large number of arrests and citations, and act as if there were a single community standard for conduct, rather than different standards for different groups. However, the fact that certain groups are more likely to have law enforcement contact means this strict enforcement of laws may seem overly harsh on certain groups;

  • Service. Emphasizes the service functions of police work, usually found in suburban, middle-class communities where residents demand individual treatment. Police in homogeneous communities can view their work as protecting their citizens against “outsiders”, with frequent but often-informal interventions against community members. The uniform make-up of the community means crimes are usually more obvious, and therefore less frequent, leaving police free to deal with service functions, and traffic control.


Wilson’s study applies to police behavior for the entire department, over time. At any given time, police officers may be acting in a watchman, service, or legalistic function by nature of what they’re doing at the time, or temperament, or mood. Individual officers may also be inclined to one style or another, regardless of supervisor or citizen demands.

Entry qualifications

Nearly all U.S. states and the federal government have by law adopted minimum-standard standardized training requirements for all officers with powers of arrest
Arrest
An arrest is the act of depriving a person of his or her liberty usually in relation to the purported investigation and prevention of crime and presenting into the criminal justice system or harm to oneself or others...

 within the state. Many standards apply to in-service training
Training
The term training refers to the acquisition of knowledge, skills, and competencies as a result of the teaching of vocational or practical skills and knowledge that relate to specific useful competencies. It forms the core of apprenticeships and provides the backbone of content at institutes of...

 as well as entry-level training, particularly in the use of firearms, with periodic re-certification required. These standards often comply with standards promoted by the US Department of Justice. These standards typically require a thorough background check
Background check
A background check or background investigation is the process of looking up and compiling criminal records, commercial records and financial records of an individual....

 that potential police recruits:
  • Be a United States citizen
    United States nationality law
    Article I, section 8, clause 4 of the United States Constitution expressly gives the United States Congress the power to establish a uniform rule of naturalization. The Immigration and Naturalization Act sets forth the legal requirements for the acquisition of, and divestiture from, citizenship of...

     (waived in certain agencies if the applicant is a lawful resident).
  • Must have a high school diploma
    High school diploma
    A high school diploma is a diploma awarded for the completion of high school. In the United States and Canada, it is considered the minimum education required for government jobs and higher education. An equivalent is the GED.-Past diploma styles:...

     or a G.E.D. and if necessary a college degree or served in the United States military without a dishonorable discharge;
  • Be in good physical and psychological condition;
  • Maintain a clean criminal record
    Criminal record
    A criminal record is a record of a person's criminal history, generally used by potential employers, lenders etc. to assess his or her trustworthiness. The information included in a criminal record varies between countries and even between jurisdictions within a country...

     without either serious or repeated misdemeanor or any felony convictions;
  • Must have a valid driver's license
    Driver's license in the United States
    In the United States, nearly all driver's licenses are issued by individual states , rather than the federal government. Drivers are normally required to obtain a license from their state of residence, and all states recognize each other's licenses for temporary visitors subject to normal age...

     with a clean driving record and that is not currently or has a history of being suspended or revoked;
  • Be of high moral character
    Good moral character
    Good moral character is a defined legal concept in United States law that details requirements for consideration for certain benefits or positions. The term is chiefly used by the federal government in immigration law, but it can also be a requirement for a particular position of employment or...

    ;
  • Not have a history of prior narcotic
    Narcotic
    The term narcotic originally referred medically to any psychoactive compound with any sleep-inducing properties. In the United States of America it has since become associated with opioids, commonly morphine and heroin and their derivatives, such as hydrocodone. The term is, today, imprecisely...

     or repeated marijuana use or alcoholism;
  • Not have a history of ethical, professional, prior employment, motor vehicle, or financial improprieties;
  • Not have a history of domestic violence
    Domestic violence
    Domestic violence, also known as domestic abuse, spousal abuse, battering, family violence, and intimate partner violence , is broadly defined as a pattern of abusive behaviors by one or both partners in an intimate relationship such as marriage, dating, family, or cohabitation...

     or mental illness
    Mental illness
    A mental disorder or mental illness is a psychological or behavioral pattern generally associated with subjective distress or disability that occurs in an individual, and which is not a part of normal development or culture. Such a disorder may consist of a combination of affective, behavioural,...

    ;
  • Not to pose a safety and security risk;
  • Be legally eligible to own and carry a firearm.


Repeated interviews, written tests, medical examinations, physical fitness tests, comprehensive background investigations
Background check
A background check or background investigation is the process of looking up and compiling criminal records, commercial records and financial records of an individual....

, fingerprint
Fingerprint
A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger. In a wider use of the term, fingerprints are the traces of an impression from the friction ridges of any part of a human hand. A print from the foot can also leave an impression of friction ridges...

ing, drug test
Drug test
A drug test is a technical analysis of a biological specimen – for example urine, hair, blood, sweat, or oral fluid / saliva – to determine the presence or absence of specified parent drugs or their metabolites...

ing, a police oral board interview, a polygraph
Polygraph
A polygraph measures and records several physiological indices such as blood pressure, pulse, respiration, and skin conductivity while the subject is asked and answers a series of questions...

 examination and consultation with a psychologist
Psychologist
Psychologist is a professional or academic title used by individuals who are either:* Clinical professionals who work with patients in a variety of therapeutic contexts .* Scientists conducting psychological research or teaching psychology in a college...

 are common practices used to review the suitability of candidates. Recruiting in most departments is competitive, with more suitable and desirable candidates accepted over lesser ones, and failure to meet some minimum standards disqualifying a candidate entirely. Police oral boards are the most subjective part of the process and often disqualifies the biggest portion of qualified candidates .Departments maintain records of past applicants under review, and refer to them in the case of either reapplication or requests from other agencies.

Despite these safeguards, some departments have at times relaxed hiring and staffing policies, sometimes in violation of the law, most often in the cases of local departments and federally funded drug task forces facing staffing shortages, attrition, and needs to quickly fill positions. This has included at times the fielding (and sometimes the arming) of uncertified officers (who may be working temporarily in what is supposed to be a provisional limited-duty status prior to certification) and the hiring of itinerant "gypsy cops"
Gypsy cop
In law enforcement, the phrase gypsy cop is slang for an itinerant lawman, a peace officer who floats from department to department regardless of, or because of, misconduct or poor job performance....

, who may have histories of poor performance or misconduct in other departments. Several serious cases of police misconduct such as the Chicago Police Department
Chicago Police Department
The Chicago Police Department, also known as the CPD, is the principal law enforcement agency of Chicago, Illinois, in the United States, under the jurisdiction of the Mayor of Chicago. It is the largest police department in the Midwest and the second largest local law enforcement agency in the...

's torture of felony suspects between 1972-1991 by and under Jon Burge
Jon Burge
Jon Graham Burge is a convicted felon and former Chicago Police Department detective and commander who gained notoriety for allegedly torturing more than 200 criminal suspects between 1972 and 1991, in order to force confessions...

, LAPD
Los Angeles Police Department
The Los Angeles Police Department is the police department of the city of Los Angeles, California. With just under 10,000 officers and more than 3,000 civilian staff, covering an area of with a population of more than 4.1 million people, it is the third largest local law enforcement agency in...

's 1991 beating of Rodney King
Rodney King
Rodney Glen King is an American best known for his involvement in a police brutality case involving the Los Angeles Police Department on March 3, 1991...

 and late-1990s LAPD Rampart Scandal
Rampart Scandal
The Rampart scandal refers to widespread corruption in the Community Resources Against Street Hoodlums anti-gang unit of the Los Angeles Police Department Rampart Division in the late 1990s. More than 70 police officers in the CRASH unit were implicated in misconduct, making it one of the most...

, the NYPD's 1970s fatal shootings of Clifford Glover (1973) and Randolph Evans
Randolph Evans
Randolph Evans was a 15-year old Brooklyn boy who was shot and killed by NYPD officer Robert Torsney on November 26, 1976. Evans was a ninth-grader at Franklin K...

 (1976), the 1980s chokeholds and shootings of Michael Stewart, Eleanor Bumpers and Edmund Perry
Edmund Perry
Edmund Perry was a 17-year-old Harlem resident who was shot to death by a plainclothes policeman on June 12, 1985. The case briefly generated a firestorm of protest in New York City when it was revealed that Perry was an honor student and was enrolled to attend Stanford on a scholarship; however,...

, the 1990s torture of Abner Louima
Abner Louima
Abner Louima is a Haitian who was assaulted, brutalized and forcibly sodomized with the handle of a bathroom plunger by New York City police officers after being arrested outside a Brooklyn nightclub in 1997....

 and shooting of Amadou Diallo
Amadou Diallo
Amadou Diallo was a 23-year-old Guinean immigrant in New York City who was shot and killed on February 4, 1999 by four New York City Police Department plain-clothed officers: Sean Carroll, Richard Murphy, Edward McMellon and Kenneth Boss. The four officers fired a total of 41 shots...

, the 2000s shootings and record-publicizing of Patrick Dorosmund, and Sean Bell, Philadelphia Police Department
Philadelphia Police Department
The Philadelphia Police Department is the police agency responsible for law enforcement and investigations within the City of Philadelphia, Pennsylvania...

's torture of suspects in the 1970s to improve then-mayor Frank Rizzo
Frank Rizzo
Francis Lazarro "Frank" Rizzo, Sr. was an American police officer and politician. He served two terms as mayor of Philadelphia, Pennsylvania, from January 1972 to January 1980; he was Police Commissioner for four years prior to that.-Police Commissioner:Rizzo joined the Philadelphia Police...

's reputation and Torrington
Torrington
-People:* Jeff Torrington, Scottish writer* George Byng, 1st Viscount Torrington, British naval officer and statesman-Places:In Australia:* Torrington, New South WalesIn Canada:* Torrington, AlbertaIn the United Kingdom:...

, Connecticut
Connecticut
Connecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...

's Tracey Thurman incident all raised questions surrounding the screening of potential recruits.

Salary

Salary varies widely for police officers, with most being among the top third of wage-earners, age 25 or older, nationwide. In May 2008, the overall median was $51,410. The median salary for those at the federal level was $46,620, compared to $57,270 for those at the state level and $51,020 for those employed by local law enforcement agencies. The top 10% earned more than $79,680 and bottom 10% less than $30,070.
Rank Minimum Salary Maximum Salary
Police Chief $90,570 $113,930
Deputy Chief $74,834 $96,209
Police Captain $72,761 $91,178
Police Lieutenant $65,688 $79,268
Police Sergeant $58,739 $70,349
Police Corporal $49,421 $61,173
Reserve Officer $0.00 $0.00


SOURCE: U.S. Department of Labor, 2010

Handguns

Police in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 usually carry a handgun
Handgun
A handgun is a firearm designed to be held and operated by one hand. This characteristic differentiates handguns as a general class of firearms from long guns such as rifles and shotguns ....

 on duty. Many are required to be armed on-duty and off-duty. Among the most common sidearms are models produced by Glock
Glock
Glock Ges.m.b.H. is a weapons manufacturer headquartered in Deutsch-Wagram, Austria, named after its founder, Gaston Glock...

, Smith & Wesson
Smith & Wesson
Smith & Wesson is the largest manufacturer of handguns in the United States. The corporate headquarters is in Springfield, Massachusetts. Founded in 1852, Smith & Wesson's pistols and revolvers have become standard issue to police and armed forces throughout the world...

, SIG Sauer
SIGARMS
SIG Sauer GmbH is the German representative of Switzerland-based manufacturing firm Swiss Arms AG, which was spun off from Schweizerische Industrie Gesellschaft in 2000. SIG Sauer Inc was established in 1985 with the name SIGARMS to import and distribute SIG firearms into the United States,...

, and Beretta
Beretta
Fabbrica d'Armi Pietro Beretta is an Italian firearms manufacturer. Their firearms are used worldwide for a variety of civilian, law enforcement, and military purposes. It is also known for manufacturing shooting clothes and accessories. Beretta is the oldest active firearms manufacturer in the...

, usually in 9mm, .40 S&W
.40 S&W
The .40 S&W is a rimless pistol cartridge developed jointly by major American firearms manufacturers Winchester and Smith & Wesson. The .40 S&W was developed from the ground up as a law enforcement cartridge designed to duplicate performance of the FBI's reduced velocity 10mm cartridge which could...

, or .45 ACP
.45 ACP
The .45 ACP , also known as the .45 Auto by C.I.P., is a cartridge designed by John Browning in 1904, for use in his prototype Colt semi-automatic .45 pistol and eventually the M1911 pistol adopted by the United States Army in 1911.-Design and history:The U.S...

. Until the 1980s, most US police carried revolver
Revolver
A revolver is a repeating firearm that has a cylinder containing multiple chambers and at least one barrel for firing. The first revolver ever made was built by Elisha Collier in 1818. The percussion cap revolver was invented by Samuel Colt in 1836. This weapon became known as the Colt Paterson...

s, typically in .38 Special
.38 Special
The .38 Smith & Wesson Special is a rimmed, centerfire cartridge designed by Smith & Wesson. It is most commonly used in revolvers, although some semi-automatic pistols and carbines also use this round...

 or .357 Magnum
.357 Magnum
The .357 S&W Magnum , or simply .357 Magnum, is a revolver cartridge created by Elmer Keith, Phillip B. Sharpe, Colonel D. B. Wesson of firearms manufacturer Smith & Wesson, and Winchester. It is based upon Smith & Wesson's earlier .38 Special cartridge. The .357 Magnum cartridge was introduced in...

 calibers, as their primary duty weapons. Since then, most have switched to semiautomatic pistols. Two key events influencing many US police forces to upgrade their primary duty weapons to weapons with greater stopping power
Stopping power
Stopping power is a colloquial term used to describe the ability of a firearm or other weapon to cause a penetrating ballistic injury to a target, human or animal, sufficient to incapacitate the target where it stands....

 were the 1980 Norco shootout
Norco shootout
The Norco shootout was an armed confrontation between five heavily armed bank robbers and deputies of the Riverside and San Bernardino County sheriff's departments in Norco, California, United States on May 9, 1980...

 and the 1986 FBI Miami shootout.

Some police departments allow qualified officers to carry shotgun
Shotgun
A shotgun is a firearm that is usually designed to be fired from the shoulder, which uses the energy of a fixed shell to fire a number of small spherical pellets called shot, or a solid projectile called a slug...

s and/or semiautomatic rifles in their vehicles for additional firepower.

Less lethal weapons

Police also often carry an impact weapon - a baton
Baton (law enforcement)
A truncheon or baton is essentially a club of less than arm's length made of wood, plastic, or metal...

, also known as a nightstick. The common nightstick and the side handle baton, have been replaced in many locations by expandable batons such as the Monadnock Auto-Lock Expandable Baton or ASP baton
ASP, Inc.
Armament Systems and Procedures, Inc. , is an offensive compliance weapons manufacturer providing equipment to law enforcement and private security companies. ASP is perhaps best known for its telescoping batons.-History:...

. One advantage of the collapsible baton is that the wearer can comfortably sit in a patrol vehicle while still wearing the baton on their duty belt. The side handle night stick usually has to be removed before entering the vehicle. Many departments also use less-lethal weapons like mace
Mace (spray)
Chemical Mace is a tear gas in the form of an aerosol spray which propels a lachrymatory agent mixed with a volatile solvent. It is sometimes used as a self-defense device...

, pepper spray
Pepper spray
Pepper spray, also known as OC spray , OC gas, and capsicum spray, is a lachrymatory agent that is used in riot control, crowd control and personal self-defense, including defense against dogs and bears...

, electroshock gun
Electroshock gun
An electroshock weapon is an incapacitant weapon used for incapacitating a person by administering electric shock aimed at disrupting superficial muscle functions. One type is a conductive energy device , an electroshock gun popularly known by the brand name "Taser", which fires projectiles that...

s, and beanbag
Flexible baton round
A bean bag round, also known by its trademarked name flexible baton round, is a baton round fired as a shotgun shell used for less lethal apprehension of suspects.-Description:...

 shotgun rounds.

Another less lethal weapon that police officers often carry is an electroshock gun, also known as a taser
TASER International
Taser International, Inc. is a developer, manufacturer, and distributor of the Taser less-lethal electroshock guns in the United States. It is based at Scottsdale, Arizona, United States. Taser is the most common brand of electroshock gun.-History:...

. The handheld electroshock weapon was designed to incapacitate a single person from a distance by using electrical current to disrupt voluntary control of muscles. Someone struck by a Taser experiences stimulation of his or her sensory nerves and motor nerves, resulting in strong involuntary muscle contractions. Tasers do not rely only on pain compliance, except when used in Drive Stun mode, and are thus preferred by some law enforcement over non-Taser stun guns and other electronic control weapons.

Specialized weapons

Most large police departments have elite SWAT
SWAT
A SWAT team is an elite tactical unit in various national law enforcement departments. They are trained to perform high-risk operations that fall outside of the abilities of regular officers...

 units which are called in to handle situations, such as barricaded suspects, hostage situations and high-risk warrant service, that require greater force, specialized equipment, and special tactics. These units usually have submachine gun
Submachine gun
A submachine gun is an automatic carbine, designed to fire pistol cartridges. It combines the automatic fire of a machine gun with the cartridge of a pistol. The submachine gun was invented during World War I , but the apex of its use was during World War II when millions of the weapon type were...

s, automatic carbine
Carbine
A carbine , from French carabine, is a longarm similar to but shorter than a rifle or musket. Many carbines are shortened versions of full rifles, firing the same ammunition at a lower velocity due to a shorter barrel length....

s or rifle
Rifle
A rifle is a firearm designed to be fired from the shoulder, with a barrel that has a helical groove or pattern of grooves cut into the barrel walls. The raised areas of the rifling are called "lands," which make contact with the projectile , imparting spin around an axis corresponding to the...

s, semiautomatic combat shotgun
Combat shotgun
A combat shotgun is a shotgun that is intended for use in an offensive role, typically by a military force. The earliest shotguns specifically designed for combat were the trench guns or trench shotguns issued in World War I...

s, sniper rifle
Sniper rifle
In military and law enforcement terminology, a sniper rifle is a precision-rifle used to ensure more accurate placement of bullets at longer ranges than other small arms. A typical sniper rifle is built for optimal levels of accuracy, fitted with a telescopic sight and chambered for a military...

s, gas, smoke and flashbang grenade
Grenade
A grenade is a small explosive device that is projected a safe distance away by its user. Soldiers called grenadiers specialize in the use of grenades. The term hand grenade refers any grenade designed to be hand thrown. Grenade Launchers are firearms designed to fire explosive projectile grenades...

s, and other specialized weapons and equipment at their disposal. A few departments have an armored vehicle
Armoured personnel carrier
An armoured personnel carrier is an armoured fighting vehicle designed to transport infantry to the battlefield.APCs are usually armed with only a machine gun although variants carry recoilless rifles, anti-tank guided missiles , or mortars...

 for especially dangerous work.

Body armor

Uniformed police officers are often issued body armor, typically in the form of a lightweight Level IIA, II or IIIA vest that can be worn under service shirts. SWAT teams typically wear heavier Level III or IV tactical armored vests, often with steel or ceramic trauma plates, comparable to those worn by US military personnel engaged in ground operations. Officers trained in bomb disposal
Bomb disposal
Bomb disposal is the process by which hazardous explosive devices are rendered safe. Bomb disposal is an all encompassing term to describe the separate, but interrelated functions in the following fields:*Military:...

 wear specialized heavy protective armor designed to protect them from the effects of an explosion when working around live ordnance.

Police communications

Most American police departments are dispatched from a centralized communications center
Communications center
In telecommunication, the term communications center has the following meanings:# An agency charged with the responsibility for handling and controlling communications traffic...

, using VHF, UHF or, more recently, digitally trunked radio transceivers mounted in their vehicles, with individual officers carrying portable handsets or ear-worn headsets for communication when away from their vehicles. American police cars are also increasingly equipped with portable computers linked by radio to a network allowing them access to state department of motor vehicles
Department of Motor Vehicles
In the United States of America, a Department of Motor Vehicles is a state-level government agency that administers vehicle registration and driver licensing. Similar departments exist in Canada...

 information, criminal records, and other important information.

Most police communications are now conducted within a regional pool of area 911 operators using 911 and 911 telephone taxation. A large number of police agencies have pooled their 911 tax resources for Computer Aided Dispatching (CAD) to streamline dispatching and reporting.

National Law Enforcement Telecommunications System

National Law Enforcement Telecommunications System is a secure information sharing system for state and local law enforcement agencies
Law enforcement agency
In North American English, a law enforcement agency is a government agency responsible for the enforcement of the laws.Outside North America, such organizations are called police services. In North America, some of these services are called police while others have other names In North American...

. It provides electronic messaging
Electronic messaging
Electronic messaging may refer to:One to One communication*Instant message *Personal message *Text message *SMTP *Email...

 to allow information exchange between state, local, and federal agencies and support services to justice-related computer programs. The network is operated by Nlets, a non-profit corporation owned and operation by the states and funded solely by fees for service.

The network operates primarily through a secure private network through which each state has an interface to the network, and all agencies within the state operate through this portal. The federal and international components operate very similarly. Users include all U.S. states and territories, Federal agencies with a justice mission, and certain international agencies. The primary operational site for the network is housed in Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

, with a secure backup site located in the East Central U.S. for full continuity of operations in less than thirty minutes.

Information exchange is voluntary and includes everything from motor vehicle registrations, driver's data, Interpol
Interpol
Interpol, whose full name is the International Criminal Police Organization – INTERPOL, is an organization facilitating international police cooperation...

 warrants, Canadian 'Hot File' records, and U.S. Citizenship and Immigration Services (USCIS) databases, to state criminal history records. Nearly 90 million messages are sent each month.

See also

  • Law enforcement in Canada
  • List of U.S. state and local law enforcement agencies
  • Police
    Police
    The police is a personification of the state designated to put in practice the enforced law, protect property and reduce civil disorder in civilian matters. Their powers include the legitimized use of force...

  • Police ranks in the US
    Police ranks of the United States
    The United States police rank model is generally paramilitary in structure.-Ranks:Although the large and varied number of federal, state, and local police and sheriff's departments have different ranks, a general model, from highest to lowest rank, would be:...



Related:
  • Crime in the United States
    Crime in the United States
    Crime statistics for the United States are published annually by the Federal Bureau of Investigation in the Uniform Crime Reports which represents crimes reported to the police...

  • Incarceration in the United States
  • Terrorism in the United States
    Terrorism in the United States
    A common definition of terrorism is the systematic use or threatened use of violence to intimidate a population or government and thereby effect political, religious, or ideological change...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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