Law enforcement in the United States/sandbox

Law enforcement in the United States is one of three major components of the criminal justice system of the United States, along with courts and corrections. Although each component operates semi-independently, the three collectively form a chain leading from investigation of suspected criminal activity to administration of criminal punishment. Also, courts are vested with the power to make legal determinations regarding the conduct of the other two components.

Law enforcement operates primarily through governmental police agencies. The law-enforcement purposes of these agencies are the investigation of suspected criminal activity, referral of the results of investigations to the courts, and the temporary detention of suspected criminals pending judicial action. Law enforcement agencies, to varying degrees at different levels of government and in different agencies, are also commonly charged with the responsibilities of deterring criminal activity and preventing the successful commission of crimes in progress. Other duties may include the service and enforcement of warrants, writs, and other orders of the courts.

Law enforcement agencies are also involved in providing first response to emergencies and other threats to public safety; the protection of certain public facilities and infrastructure; the maintenance of public order; the protection of public officials; and the operation of some correctional facilities (usually at the local level).

Types of police
Policing in the United States is conducted by "close to 18,000 federal, state, local and city departments". Every state has its own nomenclature for agencies, and their powers, responsibilities and funding vary from state to state.

Federal
<!-- At the federal level, there exist both federal police, who possess full federal authority as given to them under United States Code (U.S.C.), and federal law enforcement agencies, who are authorized to enforce various laws at the federal level. Both police and law enforcement agencies operate at the highest level and are endowed with police roles; each may maintain a small component of the other (for example, the FBI Police). 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.

The Department of Justice (DOJ) is responsible for most law enforcement duties at the federal level. It includes the Federal Bureau of Investigation (FBI), the Drug Enforcement Administration (DEA), the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF), the United States Marshals Service, the Federal Bureau of Prisons (BOP) and others.

The Department of Homeland Security (DHS) is another branch with numerous federal law enforcement agencies reporting to it. U.S. Customs and Border Protection (CBP), U.S. Immigration and Customs Enforcement (ICE), Federal Air Marshal Service (FAMS), United States Secret Service (USSS), United States Coast Guard (USCG), Homeland Security Investigations (HSI), and the Transportation Security Administration (TSA) are some of the agencies that report to DHS. It should be noted that the United States Coast Guard is assigned to the United States Department of Defense in the event of war.

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 agreements, for example the United States Federal Protective Service responded to the Hurricane Katrina natural disaster. Command in such situations remains a complex and flexible issue.

In accordance with the federal, as opposed to unitary or confederal, structure of the United States government, the national (federal) government is not authorized to execute general police powers by the Constitution of the United States of America. Each of the United States' 50 federated states (referred to simply as 'states' in the United States despite their lack of full sovereignty) retain their own police, military and domestic law-making powers. The US 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 US state and the fugitive does not flee the state, the federal government has no jurisdiction. However, once the fugitive crosses a state line they violate the federal law of interstate flight and is subject to federal jurisdiction, at which time federal law enforcement agencies may become involved. --> XXXX

State
Most states operate statewide government agencies that provide law enforcement duties, including investigations and state patrols. They may be called state police or highway patrol, and are normally part of the state Department of Public Safety. In addition, the Attorney General's office of each state has its own state bureau of investigation. In Texas, the Texas Ranger Division 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 divisions, such as capitol police, campus police, state hospitals, Departments of Correction, water police, 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's department which only handles minor issues such as service of papers and 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 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 services to special districts within the county.
 * 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 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 states maintain county detectives in their county attorneys' offices.

For example, the Commonwealth of Virginia does not have overlapping County and City jurisdictions, whereas in the other 49 states most municipalities fall within (and share jurisdiction and many other governmental responsibilities with) a County. In Virginia, governmental power flows down from the State (or in Virginia's case, Commonwealth) directly to either a County or an Independent City. Thus, policing in Virginia is somewhat simplified where a County Sheriff's Office/Department or County Police Department does not overlap with an Independent City Police Department. Unincorporated Townships remain part of their parent County, but may have Town Police Departments to augment their County law enforcement. Town Police Departments are often small, and may deploy a combination of paid and nonpaid, full and part-time law enforcement officers, including auxiliary officers who typically serve as part-time, unpaid volunteers. If present, Independent City Sheriff's Offices usually follow the Restrictive model shown below for Sheriff's Departments, with limited law enforcement authority including warrant service, jail bailiff, etc. Mutual assistance compacts may exist where neighboring law enforcement agencies will assist each other, however, in addition to State (Commonwealth) law enforcement resources.

Sheriff’s 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 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 prisoners, providing courthouse security and other duties with regard to service of process and summonses that are issued by county and state courts. The sheriff also often conducts auction sales of real property in foreclosure 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 or constable.
 * In Texas, the sheriff's office is normally the agency responsible for handling mental health calls. If the situation is dangerous, a sheriff's deputy has the power to take a person to a hospital on a mental health commitment immediately. However, if the situation is not actively dangerous, a warrant must be sought. With the rise in mental health units across the state, the Texas CIT Association was formed.

Municipal

 * See Municipal police departments of the United States for a list

Municipal police range from one-officer agencies (sometimes still called the town marshal) to the 50,000 person-strong New York City Police Department. 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, 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 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, 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, are contracted to provide full police services to local cities within their counties.

Other

 * See Specialist police departments of the United States for a list

There are other types of specialist police departments with varying jurisdictions. Most of these serve special-purpose districts and are known as special district police. In some states, they serve as little more than security police, 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, school district police, campus police, airport police, railroad police, park police or police departments responsible for protecting government property, such as the former Los Angeles General Services Police. 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.


 * Puerto Rico Police

The Puerto Rico Police 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 Puerto 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 had over 17,292 officers.

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, murder, or 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, providing tourist information, guiding the disoriented, or acting as educators (on topics such as preventing drug use). 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.

History
Early policing in American history was based on the ancient English common law system which relied heavily on citizen volunteers, watch groups, and a conscription system known as posse comitatus similar to the militia system, which continued until the mid-Nineteenth century.

Police reform
There have been many initiatives to reform policing, notably since the 1960s, under President Lyndon Johnson, and several more recent efforts. Police departments across the country continue to be scandalized by instances of corruption and brutality. Reforms based on community dialogue, legal requirements and updating of police training is growing.

Militarization of police
The militarization of both rural and urban law enforcement has been attributed to the United States' involvement in wars during the 20th century, although some attribute the militarization to the more recent campaigns on drugs and terror. Historian Charles Beard argues that cultural change during the Great Depression encouraged the militarization of law enforcement, whereas Harwood argues that the creation of SWAT teams and tactical units within law enforcement during the 1960s began such trend.

In recent years, the use of military equipment and tactics for community policing and for public order policing has become more widespread under the 1033 program. The program prompted discussion among lawmakers in 2014 after unrest in Ferguson, Missouri. President Obama introduced restrictions in 2015 on the transfer of surplus military equipment to police. In 2017, the Trump administration announced it will reinstate the program.

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. Researchers Falcone, Wells, & Weisheit’s describe a historical separation of police models between small towns and larger cities. The distinction has also been defined between rural and urban policing models, which tended to function differently with separate hierarchical systems supporting each.

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.

Community-oriented policing is a shift in policing practices in the U.S. that moved away from standardization and towards a more preventative model where police actively partner with the community it serves.

General powers
Law enforcement officers are granted certain powers to enable them to carry out their duties. When there exists probable cause to believe that a person has committed a serious crime, a law enforcement officer can handcuff and arrest a person, who will be held in a police station or jail pending a judicial bail determination or an arraignment.

The procedural use of strip searches and cavity searches by law enforcement has raised civil liberties concerns. The practice of taking an arrested person on a perp walk, often handcuffed, through a public place at some point after the arrest, creating an opportunity for the media to take photographs and video of the event, has also raised concerns.

In 2010, the FBI estimated that law enforcement agencies made 13,120,947 arrests (excluding traffic violations). Of those persons arrested, 74.5% were male and 69.4 percent of all persons arrested were white, 28.0 percent were black, and the remaining 2.6 percent were of other races.

A law enforcement officer may briefly detain a person upon reasonable suspicion of involvement in a crime but short of probable cause to arrest. Contrary to popular belief and Hollywood-style depictions in TV and movies, merely lawfully detaining a person—in and of itself—does not deprive a person of their Fourth Amendment right against unlawful searches. Federal, state, and local laws, and individual law enforcement departmental policies govern when, where, how, and upon whom a law enforcement officer may perform a "pat down," "protective search," or "Terry frisk," based on several U.S. Supreme Court decisions (including Terry v. Ohio (1968), Michigan v. Long (1983), and Maryland v. Buie (1990)): In Terry v. Ohio, the landmark decision introducing the term "Terry frisk," or "frisk," to the broader public:

"Our evaluation of the proper balance that has to be struck in this type of case leads us to conclude that there must be a narrowly drawn authority to permit a reasonable search for weapons for the protection of the police officer, where he has reason to believe that he is dealing with an armed and dangerous individual, regardless of whether he has probable cause to arrest the individual for a crime. The officer need not be absolutely certain that the individual is armed; the issue is whether a reasonably prudent man in the circumstances would be warranted in the belief that his safety or that of others was in danger (italics added)."

The New York City Police Department came under scrutiny in 2012 for its use of a stop-and-frisk program.

Civil asset forfeiture
The Supreme Court ruled that law enforcement officers may enter a house without knocking if they have “a reasonable suspicion” that announcing their presence would be dangerous or allow a suspect to destroy evidence (for example, by flushing drugs down the toilet). In addition, rules on civil asset-forfeiture allow law enforcement officers to seize anything which they can plausibly claim was the proceeds of a crime. The property-owner need not be convicted of that crime; if officers find drugs in a house, they can take cash from the house and possibly the house itself. Commentators have said these rules provide an incentive for law enforcement officers to focus on drug-related crimes rather than rape and murder investigations. They also provide an incentive to arrest suspected drug-dealers inside their houses, which can be seized, and to raid stash houses after most of their drugs have been sold, when officers can seize the cash.

Deadly force
Use of deadly force is often granted to law enforcement officers when the person or persons in question are believed to be an immediate danger to people around them, or when a person poses a significant threat to a law enforcement officer, usually when the officer is at risk of serious bodily injury or death. Most law enforcement agencies establish a use of force continuum and list deadly force as a force of last resort. With this model, agencies try to control excessive use of force. Nonetheless, some question the number of killings by law enforcement officers, including killings of people who are unarmed, raising questions about widespread and ongoing excessive use of force. Other non-fatal incidents and arrests have raised similar concerns.

Misconduct
Several serious cases of police misconduct have raised questions surrounding abuse of powers by individual or groups of officers. Historical examples include the Chicago Police Department's torture of felony suspects between 1972-1991 by and under Jon Burge, Los Angeles Police Department's 1991 beating of Rodney King and late-1990s LAPD Rampart Scandal, New York City Police Department's 1970s fatal shootings of Clifford Glover (1973) and Randolph Evans (1976), the 1980s chokehold of Michael Stewart (1983), shootings of Eleanor Bumpers (1984) and Edmund Perry (1985), the stun gun torture of Mark Davidson (1985), the 1990s torture of Abner Louima and shooting of Amadou Diallo, the 2000s shootings and record-publicizing of Patrick Dorismond, and Sean Bell, Philadelphia Police Department's torture of suspects in the 1970s to improve then-mayor Frank Rizzo's reputation and Torrington, Connecticut's Tracey Thurman.

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 within the state. Many standards apply to in-service training 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 that potential police recruits:
 * Be a United States citizen (waived in certain agencies if the applicant is a lawful resident).
 * Must have a high school diploma or a GED and if necessary a college degree or served in the United States military without a dishonorable discharge;
 * Be in good medical, physical, and psychological condition;
 * Maintain a clean criminal record without either serious or repeated misdemeanor or any felony convictions;
 * Must have a valid driver's license with a clean driving record and that is not currently or has a history of being suspended or revoked;
 * Be of high moral character;
 * Not have a history of prior narcotic or repeated marijuana use or alcoholism;
 * Not have a history of ethical, professional, prior employment, motor vehicle, educational, or financial improprieties;
 * Not have a history of domestic violence or mental illness;
 * 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, fingerprinting, drug testing, a police oral board interview, a polygraph examination and consultation with a psychologist 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 between other agencies.

Issues with recruitment
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", who may have histories of poor performance or misconduct in other departments.

Firearms
Police in the United States usually carry a handgun on duty. Many are required to be armed on-duty and often required to have a concealable off-duty handgun. Among the most common sidearms are models produced by Glock, Smith & Wesson, SIG Sauer, Beretta, and Heckler & Koch, usually in 9mm, .40 S&W, .357 SIG (US Secret Service and other Federal Law Enforcement agencies) or .45 ACP.

Until the late 1980s and early 1990s, most US police officers carried revolvers, typically in .38 Special or .357 Magnum calibers, as their primary duty weapons. At the time, Smith & Wesson, Colt, Ruger and some Taurus models were popular with police officers, most popular being the Smith & Wesson or Colt revolvers. Since then, most agencies 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 and round capacity were the 1980 Norco shootout and the 1986 FBI Miami shootout.

Some police departments allow qualified officers to carry shotguns and/or semiautomatic rifles in their vehicles for additional firepower, typically to be used if a suspect is involved in an active shooter situation, or a hostage/barricade incident.

Less lethal weapons


Police also often carry an impact weapon - a baton, 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. 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, pepper spray, electroshock guns, and beanbag shotgun rounds.

Another less lethal weapon that police officers often carry is an electroshock gun, also known as a Taser. The handheld electroshock weapon was designed to incapacitate a single person from a distance by using electric 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 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 guns, automatic carbines or rifles, semiautomatic combat shotguns, sniper rifles, gas, smoke and flashbang grenades, and other specialized weapons and equipment at their disposal. Some departments are equipped with armored vehicles.

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 U.S. military personnel engaged in ground operations. Officers trained in bomb disposal wear specialized heavy protective armor designed to protect them from the effects of an explosion when working around live ordnance. Local police foundations have initiated programs to provide law enforcement agencies with higher level vests that provide greater protection and vests for police K-9s as well.

Body-worn camera
Multiple states have pending body-worn camera legislation that require its law enforcement to be equipped with body-worn cameras when the officers are on duty. Some of these states include California, Washington, and Illinois, among others. Body-worn cameras are video recording devices around three inches long that cost between $129-$900. There are different body-worn camera models, but a standard body-worn camera includes an on and off switch that enables the image capturing technology to record and store data in the cloud.

Body-worn cameras have become standard due to the rise of civilian complaints about police brutality across the nation. Supporters argue that the use of a body-worn camera allows evidence to be viewed from an unbiased perspective. Corporations are currently working on body-worn camera models that will resolve the technology’s limitations such as better audio capturing technology and battery life, to name a few. Surveillance items that can be used by law enforcement which have been scrutinized also include the Automatic number plate recognition due to it's similarities to mass surveillance.

Police communications
Most American police departments are dispatched from a centralized communications center, 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 mobile data terminals (MDT's)or portable computers linked by radio to a network allowing them access to state department of motor vehicles information, criminal records, and other important information.

Most police communications are now conducted within a regional pool of area telecommunicators or dispatchers using 9-1-1 and 9-1-1 telephone taxation. A large number of police agencies have pooled their 9-1-1 tax resources for Computer Aided Dispatching (CAD) to streamline dispatching and reporting. CAD systems are usually linked to MDT's (see above).

Information sharing
A variety of national, regional, state and local information systems are available to law enforcement agencies in the U.S., with differing purposes and types of information. One unique example is the National Law Enforcement Telecommunications System (NLETS). NLETS an interstate justice and public safety network owned by the states supporting inquiry into state systems for criminal history, driver’s license and motor vehicle registration, as well as supporting inquiry into federal systems, such as the Department of Homeland Security (DHS) U.S. Immigration and Customs Enforcement (ICE) Law Enforcement Support Center, the Drug Enforcement Administration (DEA) National Drug Pointer Index (NDPIX), and the Federal Aviation Administration (FAA) Aircraft Registry, as well as the Government of Canada’s Canadian Police Information Centre (CPIC).

NLETS 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 United States and territories, Federal agencies with a justice mission, and certain international agencies. The primary operational site for the network is housed in Arizona, with a secure backup site located in the East Central U.S.

Through the Nlets network, law enforcement and criminal justice agencies can access a wide range of information, from standard driver license and vehicle queries to criminal history and Interpol information. Operations consist of nearly 1.5 billion transactions a year to over 1 million PC, mobile and handheld devices in the U.S. and Canada at 45,000 user agencies and to 1.3 million individual users.

Number of police
In 2008, federal police employed approx. 120,000 full-time law enforcement officers, authorized to make arrests and carry firearms in the United States.

The 2012 Bureau of Justice Statistics' Census of State and Local Law Enforcement Agencies (CSLLEA), found there were 17,985 state and local law enforcement agencies employing at least one full-time officer or the equivalent in part-time officers.

In 2008, state and local law enforcement agencies employed more than 1.1 million people on a full-time basis, including about 765,000 sworn personnel (defined as those with general arrest powers). Agencies also employed approximately 100,000 part-time employees, including 44,000 sworn officers.

From 2004 to 2008, overall full-time employment by state and local law enforcement agencies nationwide increased by about 57,000 (or 5.3%). Sworn personnel increased by about 33,000 (4.6%), and nonsworn employees by about 24,000 (6.9%). From 2004 to 2008, the number of full-time sworn personnel per 100,000 U.S. residents increased from 250 to 251. From 1992 to 2008, the growth rate for civilian personnel was more than double that of sworn personnel.

Local police departments were the largest employer of sworn personnel, accounting for 60% of the total. Sheriffs' offices were next, accounting for 24%. About half (49%) of all agencies employed fewer than 10 full-time officers. Nearly two-thirds (64%) of sworn personnel worked for agencies that employed 100 or more officers.

Changes in personnel numbers
Fifteen of the 50 largest local police departments employed fewer full-time sworn personnel in 2008 than in 2004. The largest declines were in Detroit (36%), Memphis (23%), New Orleans (13%), and San Francisco (10%).

Ten of the 50 largest local police departments reported double-digit increases in sworn personnel from 2004 to 2008. The largest increases were in Phoenix (19%), Prince George's County (Maryland) (17%), Dallas (15%), and Fort Worth (14%).

Salary
Salary varies widely for police officers, with most being among the top third of wage-earners, age 25 or older, nationwide. In May 2012, the overall median was $56,980. The top 10% earned more than $93,450 and bottom 10% less than $33,060.

The median wages for police and detective occupations in May 2012 were as follows:
 * $74,300 for detectives and criminal investigators
 * $55,270 for police and sheriff’s patrol officers
 * $55,210 for transit and railroad police
 * $48,070 for fish and game wardens