Definition
The term "police" carries two related but legally distinct meanings that have coexisted across centuries of Anglo-American law:
1. As a governmental function: The broad power of the state to regulate conduct in the interest of public order, safety, health, morals, and welfare. In this sense, "police" is less an institution than a constitutional concept — the inherent authority of sovereign government to impose reasonable restraints on persons and property for the common good. This is the sense invoked in discussions of the "police power," which is the foundational legislative and regulatory authority reserved to the states under the American constitutional structure.
2. As an organized body of officers: The institutional arm of government tasked with preserving public order, enforcing laws, preventing and detecting crime, and, in historical usage, administering local regulations touching health, cleanliness, and public safety. In modern American usage, "the police" almost always refers to this institutional body — a law enforcement agency operating at the municipal, county, or state level.
The two meanings are not unrelated: the institutional police derive their authority from, and are bounded by, the governmental police function.
Common Language
Modern common usage (Wiktionary): A constituted body of officers representing the civil authority of government, empowered to maintain public order and safety, enforce the law, and prevent, detect, and investigate crime.
Historical common usage (Webster's 1913): A judicial and executive system for the government of a city, town, or district, for the preservation of rights, order, cleanliness, health, etc., and for the enforcement of the laws and prevention of crime; also, the internal regulation of a state.
Editorial note: Modern common usage has collapsed the two historical meanings into one, equating "police" almost entirely with the uniformed law enforcement institution. Legal and constitutional usage preserves the broader governmental-function meaning — a distinction that becomes critical in police power doctrine, where "police" describes a sovereign capacity that neither requires officers nor has any necessary connection to crime. A researcher who reads "police" in an 18th- or 19th-century legal text as synonymous with "law enforcement officers" will routinely misread the source.
Common Confusion
Police vs. Police Power: These terms share a root but operate differently in legal discourse. "Police" in the institutional sense describes a government body; "police power" describes a constitutional category of sovereign authority. Confusion between them leads researchers to misinterpret constitutional cases: when a 19th-century court upholds a state's "police" authority to regulate liquor sales or quarantine disease, it is not discussing law enforcement officers — it is invoking a doctrine of inherent governmental sovereignty. The two concepts must be tracked separately in any research corpus spanning constitutional law and administrative law.
Recognized Forms
/SUBTYPES
Historical dictionaries, particularly Anderson's and Bouvier's, recognized a functional subdivision of police in the abstract governmental sense:
Administrative police: The branch concerned with the ongoing regulation of public affairs — licensing, sanitation, public works, and general welfare administration.
Preventive police: The branch concerned with anticipating and forestalling threats to public order and safety before crimes are committed, as distinguished from reactive enforcement.
These subcategories appear primarily in 19th-century civil law-influenced sources and in treatises drawing on French and continental administrative theory. They are rarely used in contemporary American legal practice but surface in historical research on municipal governance, public health law, and early administrative law.
Why It Matters in Research
The single greatest research trap with this term is temporal: the meaning of "police" in legal texts has narrowed dramatically over two centuries. Before the mid-19th century, legal writers — following Bentham, Blackstone, and continental sources — used "police" to encompass the entire system of internal state governance touching welfare, morals, health, and order. The organized uniformed institution we now call "the police" was a relatively late development in Anglo-American governance, emerging in recognizable form in England after 1829 and in American cities through the 1840s and 1850s. A researcher reading pre-Civil War American legal materials must remain alert to context: "police" may refer to the governmental function, to local regulatory officers with limited powers, or to nascent municipal constabularies, depending on the source.
In constitutional law research, the distinction between the institutional and functional meanings drives entirely different bodies of doctrine. Cases discussing the limits of "police" regulation — taxation, eminent domain, due process — draw on the police power doctrine. Cases discussing search and seizure, use of force, civil rights liability under 42 U.S.C. § 1983, and qualified immunity draw on the institutional meaning and its constitutional constraints. These bodies of law meet but do not merge, and conflating the terms will send a researcher into the wrong case law.
Jurisdictional variation matters in the institutional sense: the organizational structure, powers, and accountability mechanisms of police forces differ significantly across municipal, county, and state levels, and across jurisdictions. In the functional sense, police power doctrine is formally a reserved state power under the Tenth Amendment, but federal regulatory authority operating under the Commerce Clause has encroached extensively on what was once considered exclusively state police terrain.
The Law Mind corpus is likely to contain the functional meaning predominantly in constitutional law, administrative law, and historical treatise materials, and the institutional meaning predominantly in criminal procedure, civil rights, and municipal law materials. Researchers should calibrate search strategies accordingly.
Historical Dictionary Support
The historical dictionaries show substantial agreement on the functional definition of police as a system of governmental regulation aimed at public order and welfare, while varying in how prominently they foreground the institutional officers.
Black's Law Dictionary (both editions) offers the most analytically developed definition of the functional sense, drawing on Cooley's Constitutional Limitations and citing Bentham. The definition is notably comprehensive: it encompasses not only crime prevention but health, safety, morals, and even "the rules of good manners and good neighborhood" — language that reflects 19th-century natural law influences on constitutional theory. The Cooley quotation is particularly significant as it anchors police power in a tradition of restrained but genuine sovereign authority.
Bouvier's Law Dictionary explicitly recognizes three significations of the word — good general awareness of the term's polysemy — while centering on the magistracy-and-order understanding that reflects Bouvier's civil law training.
Rapalje & Lawrence and Anderson's offer briefer but consistent treatments. Anderson's subdivision into administrative and preventive police reflects continental influence, likely French administrative law theory, and is the most analytically precise of the shorter entries.
Burrill's Law Dictionary stands apart: its entry is a false friend. The fragment preserved in the source material addresses "police" in the sense of "policy" — specifically, a policy of insurance (police d'assurance in French). This is the French false cognate, not the governmental function. Researchers using Burrill for this term should discard the entry for present purposes, though it is a reminder that in French-derived legal sources and in early maritime and insurance law texts, "police" may refer to an insurance policy, not a governmental institution or function.
What the historical dictionaries collectively understate is the constitutional architecture that developed around the functional sense: the police power doctrine as a defined limit on federal power and a reservoir of state regulatory authority, which became a central battleground of American constitutional law from the antebellum period through the New Deal.
Jurisdictional Note
In the institutional sense, police organization is almost entirely a matter of state and local law; there is no single national police force in the United States, and federal law enforcement agencies operate under distinct statutory frameworks. In the functional sense, police power doctrine is expressly a state constitutional concept, though federal regulatory authority has substantially occupied many fields once understood as state police prerogatives.
Encyclopedia Cross-Reference
Constitutional Dimensions of Policing — Use of Force, Racial Profiling, and Reform (Law Mind Constitutional Law Encyclopedia)