If a city has its own police, what does the national force still do there?

Some policing problems are irreducibly local — markets, noise, parking, licensed premises, neighbourhood disorder — and a national force has little reason to prioritise them. A municipal tier ties those decisions to the authority that answers to the people affected.

AnalysisWhat that tier is not given is the serious end of criminal policing, which almost everywhere stays national or regional. That is why municipal forces so often hold narrower powers rather than the same powers in a smaller area.

The French provision is unusually explicit about the relationship and is worth reading closely: municipal police agents act under the authority of the mayor on tasks within the mayor’s competence relating to prevention and surveillance of public order, tranquillity, security and public health — expressly without prejudice to the general competence of the national police.

• The national force keeps general competence everywhere, including inside the municipality.
• The municipal force is defined by the mayor’s competences, which are narrower than the criminal law.
• Serious criminal investigation normally sits with the national or regional force regardless of where the offence occurred.
• Where a third tier exists, as in Spain, the picture is not two forces dividing work but three bodies with distinct legal bases.

Spain sets that three-tier structure out in its organic law on security forces, naming state security forces, the police of the autonomous communities, and local police.

• Common belief: A city police force replaces the national police inside the city.

  In practice: It does not. In France the provision creating municipal police expressly preserves the general competence of the national police in the same territory.

• Common belief: Municipal officers have the same powers as national officers.

  In practice: Municipal powers are normally narrower, defined by the local authority’s competences rather than by the criminal law.

• Common belief: Every country with municipalities has municipal police.

  In practice: Japan administers policing at prefectural level and its municipalities do not own ordinary police forces. The existence of city government implies nothing about a city force.

• Common belief: Where two forces operate, one is a junior branch of the other.

  In practice: They answer to different authorities. A municipal agent answers to the mayor, not to the national force operating in the same street.

• Whether a municipality may create a force at all is set nationally, and in many countries it may not.
• The powers available to municipal officers vary from full police powers to a narrow regulatory set.
• Whether municipal officers are armed is a national policy question answered differently across neighbouring countries.
• A third regional tier may exist between municipal and national, as in Spain, which changes the relationship entirely.

France

Article L511-1 of the Code de la sécurité intérieure places municipal police agents under the mayor’s authority for prevention and surveillance of public order, tranquillity, security and public health — and opens by preserving the general competence of the national police. The municipal tier is defined in law as an addition, not a substitute.

Spain

Organic Law 2/1986 structures policing in three tiers — state security forces, the police of the autonomous communities, and local police — so a Spanish city force operates in a territory where a regional force may also be present. Three tiers, not two.

Japan

Japanese municipalities do not own ordinary police forces. Policing is administered at prefectural level under a national framework, so the presence of city government implies nothing about a city police department. "Municipality" and "municipal police" are not linked.

The practical consequence is the one that recurs across this cluster: the complaint route follows the force. A municipal officer and a national officer standing in the same street may be answerable to entirely different bodies, and the person affected frequently cannot tell them apart.

Related: municipal police, neighbourhood policing as a function, local police governance, and France.