What does police jurisdiction mean, and can two agencies have it at once?

Societies rarely design policing once. They add layers — a city force, then a state or provincial one, then a national body for offences that cross boundaries, then specialised agencies for networks and functions. Each layer is created by a different instrument for a different reason, and the result is not a hierarchy so much as an accumulation.

AnalysisThe alternative to overlap is worse. A boundary that no one may cross is a boundary an offence can be organised around, and a single agency with authority over everything is the arrangement most systems have deliberately avoided.

Two agencies can hold valid authority in the same place because their authority comes from different sources and covers different things. That is concurrent jurisdiction, and it is a design feature rather than a defect.

• A municipal force and a national force may both act in a city, one under local competence and the other under general national competence.
• A federal agency may act anywhere in the country, but only on the offences its statute names.
• A transport or network force may hold authority defined by infrastructure that crosses every local boundary on its route.
• Where several agencies may act, which one does is normally settled by protocol, seniority of offence, or agreement — not by one commanding the other.

The scale of this is easy to underestimate. In the United States there were 17,541 general-purpose state and local law-enforcement agencies at the 2018 census — roughly two-thirds local police departments and a sixth sheriffs offices — each separately governed rather than branches of one organisation.

Switzerland shows the same plurality without a federal apex: the country has no national police force, each canton polices its own territory under its own police law, and the federal office of police states that it is not a superordinate authority but works alongside the cantonal forces.

• Common belief: Only one agency can have jurisdiction in a given place.

  In practice: Concurrent jurisdiction is normal. Several agencies may each hold valid authority over the same location for different matters, derived from different instruments.

• Common belief: The agency with the widest jurisdiction is in charge.

  In practice: Breadth of jurisdiction is not seniority. A national agency may have authority over a narrow list of offences and none at all over the matter actually in front of a local officer.

• Common belief: Jurisdiction means the right to give orders to other agencies.

  In practice: It almost never does. Authority to act and authority to command are separate, and most systems keep them separate deliberately.

• Common belief: Sub-national government implies sub-national police.

  In practice: It does not. Kenya devolved substantial powers to 47 counties while keeping policing national, and Nigeria is a federation whose constitution forbids any police force other than the national one.

• Whether local government may create a police force at all is a constitutional question answered differently by different states.
• Whether a national force has general competence everywhere, or only where no local force operates, varies.
• France divides the question by authority rather than by map: municipal police agents act under the mayor for prevention and surveillance of public order, expressly without prejudice to the general competence of the national police.
• Where several forces operate in one territory, the rules on which takes primacy for which offence are national and are not portable between countries.

The French provision is a useful model of how these boundaries are actually drawn: the municipal tier is defined as an addition to national policing rather than a local replacement for it.

United States

The United States shows territorial jurisdiction at its most fragmented: 17,541 general-purpose state and local law-enforcement agencies, about 67% of them local police departments and 17% sheriffs offices, each separately governed. Overlap is not an anomaly there; it is the ordinary condition.

Switzerland

Switzerland has no national police force. Each canton polices its own territory under its own police law, and the federal office works alongside the cantonal forces rather than above them — jurisdiction distributed without a hierarchy to resolve it.

Kenya

Kenya devolved substantial government to 47 counties and kept policing national: the Constitution places police services, criminal law and correctional services with the national government. Sub-national government does not create sub-national police jurisdiction.

For a person affected by police action, the practical consequence of all this is narrow and important: the oversight body that can examine what happened follows the agency, not the place.

• Establishing which agency acted comes before any complaint, and in a fragmented system it is genuinely hard.
• A complaints body for one force commonly has no jurisdiction over another operating in the same street.
• Where an agency acts outside its jurisdiction, the consequence is usually litigated as a question about the validity of what was done rather than as a disciplinary matter alone.

Related: how policing is divided between levels of government, transport and railway policing, police command and coordination, and the institution types reference.