Law Enforcement

What is the difference between a police complaint, a misconduct investigation and a criminal investigation?

Five things get called "an investigation into the police": complaint intake, misconduct investigation, disciplinary investigation, criminal investigation and prosecution. They are separate stages held by different bodies, and some bodies hold one without the others.

Fact-checkedSafety review clearedLast updated 25 August 2026Last reviewed 25 August 2026

In short

A single phrase — "the police are being investigated" — covers five different things. Keeping them apart is the difference between understanding what a body can do and assuming it can do everything.

Complaint intake: someone tells a body that something was wrong. The body records it and decides whether it is admissible and who should handle it.
Misconduct investigation: establishing what happened, measured against standards of conduct rather than against the criminal law.
Disciplinary investigation: establishing whether an employee broke the organisation’s rules, in a process that can end in a sanction against them.
Criminal investigation: establishing whether an offence was committed, under criminal procedure and with the powers that go with it.
Prosecution: the decision to bring a criminal charge, and the conduct of the case in court.

Why it exists

The stages exist separately because they answer different questions to different standards. Whether an officer was rude, whether an officer broke a workplace rule, and whether an officer committed an assault are three questions, and the third one carries a criminal standard of proof and a set of procedural protections the first two do not.

AnalysisThis is why a complaint can be upheld while no one is prosecuted, and why an acquittal does not mean a complaint was baseless. Different findings on different standards by different bodies is a coherent result, not a contradiction.

How it works

The clearest proof that the stages are genuinely separable is that some bodies are required to refuse the ones they do not hold.

A body that must turn away non-criminal complaints: Norway’s Spesialenheten for politisaker investigates and prosecutes criminal acts committed in the course of duty by police and prosecution employees. Chapter 34 of the prosecution instruction requires its chief to reject cases outside that competence, "for eksempel fordi det anmeldte forhold ikke er straffbart" — for example because the reported matter is not criminal. A complaint that alleges no offence is not refused because the body is unwilling; it is outside the body’s statutory competence.
A body with no complaint procedure at all: Czechia’s General Inspection of Security Forces investigates crimes by officers of the police, the customs administration and the prison service. Its Act provides no complaints mechanism for those forces. A member of the public may alert the inspection to conduct by another force’s officer only where that conduct amounts to a CRIMINAL offence — while for the inspection’s own members the same provision extends to administrative and disciplinary offences. The asymmetry is written into the statute.
A body that investigates and cannot charge: New Zealand’s Independent Police Conduct Authority receives complaints, investigates incidents causing death or serious bodily harm with the powers of a Commission of Inquiry, and must determine whether police conduct was unlawful, unreasonable, unjustified, unfair or undesirable. Section 27 of its Act denies it the power to lay criminal charges or take disciplinary action. It reaches a finding and hands the decision on.
A body that investigates and prosecutes: Norway’s bureau again, at the other end. Its chief decides the prosecution question except where that belongs to the Director of Public Prosecutions, and where the unit indicts, a lawyer from the unit conducts the case in court. Investigation and prosecution in one body is the exception in this set, not the pattern.

AnalysisThe last two stages separate almost everywhere. Of the bodies researched for this cluster, one prosecutes; the rest must refer to a prosecution service — the National Prosecuting Authority in South Africa, the Director of Public Prosecutions in Kenya and Ireland, the state prosecutor in Czechia. And the disciplinary decision belongs to the police in every single case. South Africa comes closest to an exception and is worth stating precisely: on a disciplinary recommendation the Commissioner must begin proceedings within 30 days and report quarterly to the Minister. That is a duty on the police to act. It is not a power in the oversight body to decide.

Some bodies do hold several stages at once, and the page would be misleading if it implied a clean division. Denmark’s authority handles conduct complaint cases and investigates criminal cases against police and prosecution personnel. Ireland’s Fiosrú takes complaints and investigates with powers equivalent to a Garda member. Kenya’s Authority investigates disciplinary and criminal offences alike, inspects police premises and audits the internal unit. The stages are separable, which is not the same as always separated.

Common misconceptions

Widely held beliefs that do not match how the system actually operates.

Common belief: If a body is independent, it can investigate any complaint about the police.
In practice: Two bodies in this cluster that sit wholly outside the police cannot. Norway’s must reject a report disclosing no offence, and Czechia’s Act contains no complaint procedure for the forces it investigates.
Common belief: An investigation that finds wrongdoing leads to a prosecution.
In practice: In most systems the investigating body refers the file to a prosecutor, who takes the charging decision. Kenya’s Authority may require the Director of Public Prosecutions to respond to its recommendation, which is a duty to answer, not a duty to charge.
Common belief: Oversight bodies discipline officers.
In practice: Almost none do. Across the bodies researched, discipline is referred to the police hierarchy. The one conditional exception found is an internal unit — Kenya’s — and only where the Inspector-General authorises it.
Common belief: A complaint sent back to the police has been dismissed.
In practice: Several statutes route defined categories to the police deliberately, with arrangements for how they must be handled. Referral is a step in the process, not the end of it.

How this varies between jurisdictions

A required section on every guide. Arrangements differ between countries, and we say how.

Systems differ less in whether they recognise these stages than in how many of them they put in one body, and where they place the boundary between complaint and crime.

Criminal stages only: Norway and Czechia. Both bodies investigate crimes by officers and neither takes conduct complaints; Norway’s must refuse them by statute and Czechia’s Act does not provide for them.
Complaint and misconduct stages, without the criminal decision: New Zealand. The Authority receives complaints, investigates, and determines whether conduct was unlawful, unreasonable, unjustified, unfair or undesirable — and cannot lay a charge or impose a sanction.
Complaint and criminal stages together: Denmark and Ireland. Denmark’s authority handles conduct complaints and investigates criminal cases against police and prosecution personnel. Ireland’s Fiosrú determines admissibility, investigates with police-equivalent powers, and refers to the Director of Public Prosecutions.
The widest mandate found, still without the final decisions: Kenya. Complaints from the public and from officers, disciplinary and criminal investigation, inspection of police premises, audit of the internal unit, and the power to take over a delayed internal investigation — with prosecution recommended to the Director of Public Prosecutions and discipline recommended to the Service.

Worked examples

Systems this platform has researched. Each example links to the dossier it draws on.

Norway: Holds criminal investigation and prosecution and neither of the complaint stages. Its chief must reject a report that discloses no criminal offence, and where a case calls for an administrative response it goes to the officer’s own commander.
Czechia: Holds criminal investigation only. The Act gives the public a right to alert the inspection to an officer’s CRIMINAL conduct, and no complaint procedure beyond it — while the same provision covers administrative and disciplinary offences when the person complained of belongs to the inspection itself.
Ireland: Shows intake and investigation as separate decisions. Fiosrú determines admissibility, routes defined categories back to An Garda Síochána for resolution, investigates the rest with powers equivalent to a Garda member, and refers to the Director of Public Prosecutions.
South Africa: Shows the disciplinary boundary at its sharpest. The Directorate recommends; the Commissioner must initiate proceedings within 30 days and report quarterly to the Minister; the disciplinary decision remains the police service’s.

Where the pattern does not hold

Systems at the same level that arrange this differently. The pattern above is a pattern, not a rule.

Denmark: Holds the complaint and criminal stages together in one body, which is why the stages should be read as separable rather than always separate. The authority handles conduct complaint cases and investigates criminal cases against police and prosecution personnel alike.

Rights and accountability

AnalysisThe practical consequence of these distinctions is that "who investigates the police" has no single answer even inside one country, because it depends on which stage is meant. The same incident may produce a complaint handled by the police under a statutory arrangement, a criminal investigation by an external body, a prosecution decision by a prosecutor, and a disciplinary process run by the force — four processes, four bodies, four standards.

What we could not establish

The five stages described here are drawn from the instruments of the countries researched. They are a way of reading those instruments accurately, not a universal legal scheme, and a system may divide the same ground differently.
This page does not describe how to make a complaint anywhere, and it does not say what outcome any stage should produce.

When a police officer is accused of wrongdoing, who investigates?
There is no single answer, and the differences matter. This guide sets out the arrangements that recur — internal units, external statutory bodies, prosecutors, and bodies that investigate and prosecute at once — and the systems that use none of them.
Which bodies can examine what the police did, and what can each of them actually do?
Internal investigation, independent complaints bodies, inspectorates, prosecutors and courts examine police conduct in different ways and with different powers. This guide explains what each mechanism is for and why the differences between them matter to anyone trying to use one.
What is the difference between internal and external police oversight, and does external mean independent?
Internal bodies sit inside the police; external ones sit outside. The distinction is real and worth knowing, but it does not tell you which body is independent, and in several countries it does not tell you which one holds the stronger powers.

Where this connects

Institutions: Police investigative body, Police complaints body, Prosecution service.

Sources

Påtaleinstruksen (FOR-1985-06-28-1679), kapittel 34 — Saker som etterforskes av Spesialenheten for politisaker
Justis- og beredskapsdepartementet (Norway), via Lovdata · Legislation · 1985-06-28 · link verified 2026-08-25
The consolidated Norwegian prosecution instruction, chapter 34, in the version in force from 15 August 2025, read in full. Supports: that investigation of criminal acts committed in the course of duty by an employee of the police or the prosecuting authority is carried out and led by a separate central body, Spesialenheten for politisaker, which is a "riksdekkende etterforskings- og påtalemyndighet" (§ 34-1); that persons in the unit may not simultaneously be employed in the police or prosecuting authority, with a two-year quarantine for those appointed to office, and that the Ministry of Justice holds overall administrative responsibility (§ 34-1); that the Chief decides the prosecution question except where it belongs to the riksadvokaten, and conducts the case in court where the unit indicts (§ 34-3); that the Chief MUST reject cases outside the unit’s competence, "for eksempel fordi det anmeldte forhold ikke er straffbart" (§ 34-5); that investigation shall be opened even without suspicion of an offence where a person dies or is seriously injured as a result of police or prosecuting-authority duty or while in their care (§ 34-6); that the Chief shall send a case to the relevant politimester where it should be assessed administratively (§ 34-7); and that the riksadvokaten may order the unit to open, carry out and stop an investigation (§ 34-9). It does not establish complaint handling, discipline, or inspection, none of which the chapter provides for.
Zákon č. 341/2011 Sb., o Generální inspekci bezpečnostních sborů — konsolidované znění
Parlament České republiky, consolidated text via Zákony pro lidi · Legislation · 2011-11-06 · link verified 2026-08-25
The consolidated Czech Act on the General Inspection of Security Forces, version in force from 1 January 2026, read directly. Supports: that the inspection is established as an "ozbrojený bezpečnostní sbor" — an armed security force (§ 1(1)); that its director is appointed and removed by the prime minister on the government’s proposal after discussion in the Chamber of Deputies’ security committee, and is answerable to the prime minister (§ 1(2)); that it is an organisational unit of the state whose income and expenditure form a separate chapter of the state budget (§ 1(4)); that its task is to search out, detect and investigate facts indicating a crime by an officer of the Police of the Czech Republic, the Customs Administration or the Prison Service, by its own members, and by state employees of those bodies where the offence relates to their work (§ 2(1)-(2)); that it conducts reliability tests (§ 2(3)); that it monitors unlawful activity and proposes preventive measures and methodological recommendations (§ 2(4)-(5)); that it may restrict personal liberty and use coercive means (§§ 10-11, 23-27); and that the Act provides no complaint procedure, only a duty to accept an alert and reply within 30 days, which for officers of other forces is confined to conduct amounting to a CRIMINAL offence while for its own members it extends to administrative and disciplinary offences. It does not give the inspection any disciplinary power over the forces it investigates, and it does not give it prosecuting authority: the státní zástupce decides the prosecution question, and offences by the inspection’s own members are investigated by the státní zástupce. The transitional provisions (§§ 68-70) additionally support that the inspection took over the staff, property and unfinished proceedings of the Inspekce Policie České republiky, which sat within the Ministry of the Interior — establishing the predecessor relationship.
Independent Police Investigative Directorate Act 1 of 2011 — Government Gazette No. 34298
Republic of South Africa (Government Gazette, via gov.za) · Legislation · 2011-05-16 · link verified 2026-08-25
The Act as published in the Government Gazette, read in full. Supports: that "the Directorate functions independently from the South African Police Service" (§ 4(1)) — independence stated from the SERVICE, with no equivalent statement about the Minister; that the Minister nominates the Executive Director, the relevant parliamentary committee confirms or rejects within 30 parliamentary working days, the term is five years renewable once, and the Minister may remove on stated grounds (§ 6); that the Directorate MUST investigate deaths in police custody, deaths as a result of police actions, discharge of an official firearm, rape by a police officer on or off duty, rape of a person in police custody, torture or assault by an officer in execution of duty, corruption within the police, and referred matters (§ 28(1)); that it MAY investigate systemic corruption (§ 28(2)); that members of the South African Police Service AND of a Municipal Police Service must notify it immediately and report in writing within 24 hours (§ 29(1)); that the Executive Director MUST refer criminal offences to the National Prosecuting Authority for prosecution (§ 7(4)); that disciplinary matters are referred to the National or Provincial Commissioner (§ 7(6)-(7)) who must within 30 days initiate disciplinary proceedings in terms of the recommendations and report quarterly to the Minister (§ 30); and that service complaints about the SAPS transfer to the SAPS and where appropriate the Secretariat (§ 35(6)(b)). It establishes that the Directorate neither prosecutes nor disciplines.
Independent Policing Oversight Authority Act (Cap. 86), Laws of Kenya
National Council for Law Reporting (Kenya Law) · Legislation · 2011-12-09 · link verified 2026-08-25
The consolidated Act as revised by the 24th Annual Supplement (Legal Notice 221 of 2023) as at 31 December 2022, read in full. Now cited as Cap. 86; originally Act No. 35 of 2011, assented 11 November 2011, commenced 18 November 2011. Supports: that the long title provides for "civilian oversight of the work of the Police"; the objectives in § 5; that the Authority investigates complaints of disciplinary or criminal offences by any member of the Service on its own motion or on complaint and makes recommendations including for prosecution, compensation and internal disciplinary action, and must make public the response received (§ 6(a)); that it receives complaints BY members of the Service (§ 6(b)); that it monitors, reviews and audits investigations by the Internal Affairs Unit of the Service (§ 6(d)); that it conducts inspections of police premises including detention facilities (§ 6(e)); that it reviews patterns of misconduct and the functioning of the internal disciplinary process (§ 6(g)); that it publishes findings (§ 6(j)); the investigative powers including requisition, entry, seizure, statements under oath and compelling attendance of serving or retired officers (§ 7(1)(a)); that it RECOMMENDS prosecution to the Director of Public Prosecutions (§ 7(1)(a)(ix)); that it may take over inordinately delayed or manifestly unreasonable internal investigations (§ 7(1)(b)); that it may require the DPP and the Service to respond to recommendations (§ 7(1)(d)-(e)); that it must investigate deaths and serious injuries resulting from police action (§ 25); that it may NOT investigate a matter before a court or judicial tribunal (§ 26); and that after investigation it recommends prosecution, disciplinary action or procedural improvement (§ 29). It establishes that the Authority neither prosecutes nor disciplines.
Policing, Security and Community Safety Act 2024 (No. 1 of 2024)
Office of the Attorney General (Ireland), Irish Statute Book · Legislation · 2024 · link verified 2026-08-25
The Act as enacted, read for its structure and for Parts 4 and 6. Supports: that Part 6 gives the Police Ombudsman functions on complaints by members of the public (§ 195), admissibility (§ 198-199), categories of complaint suitable for resolution by An Garda Síochána (§§ 200-202), matters concerning death or serious harm (§ 203), notification of an incident of concern (§ 204), investigation in the public interest (§ 205) and of matters relating to the Garda Commissioner (§ 207), investigations (§ 208) with powers equivalent to a member of An Garda Síochána (§ 209), search of Garda premises (§ 210), referral to the Director of Public Prosecutions (§ 214) and other referrals following investigation (§ 215); that Part 4 establishes the Authority (§§ 120-122) and gives it, in Chapter 4, inspectors of policing services and a statutory inspection function (§§ 142-151); and that the Act dissolves the Policing Authority (§ 154, Chapter 6) and the Garda Síochána Inspectorate (§ 163, Chapter 7). Establishes that the Ombudsman neither prosecutes nor disciplines, that not every admissible complaint is investigated by it, and that two predecessor oversight bodies were dissolved into the new Authority.
Independent Police Conduct Authority (New Zealand) — legislation and accountability
Independent Police Conduct Authority (New Zealand) · Government publication · link verified 2026-08-25
The Authority’s own statement of its statutory functions, by section, read directly. Supports: that it operates under the Independent Police Conduct Authority Act 1988, the Crown Entities Act 2004 and the Crimes of Torture Act 1989; that as an Independent Crown Entity it is "politically independent and accountable only to Parliament for our performance and use of taxpayer funding"; that under s 12 its functions are to receive complaints alleging misconduct or neglect of duty by any member of Police, to receive complaints concerning any Police practice, policy or procedure affecting a complainant, and to investigate incidents in which a member of Police acting in execution of duty causes or appears to have caused death or serious bodily harm; that under ss 17-18 it must notify Police of complaints received and Police must notify it within five working days; that under ss 23-26 it has the same powers as a Commission of Inquiry to summon witnesses and gather evidence; that under ss 27-28 it must determine whether any Police act or omission was unlawful, unreasonable, unjustified, unfair or undesirable and may recommend, including recommending disciplinary or criminal proceedings; that under s 27 it has NO power to lay criminal charges or take disciplinary action; and that under s 29 the Attorney-General must inform Parliament where it is dissatisfied with the Police response. Cited because legislation.govt.nz returned an automated-request block; per the rule on verificationMethod that is not treated as evidence against the statute, and nothing is cited from a text that was not read.
Den Uafhængige Politiklagemyndighed — about the Police Complaints Authority
Den Uafhængige Politiklagemyndighed (Denmark) · Government publication · link verified 2026-08-25
The Authority’s own English page, read directly and re-confirmed for Wave 7. Supports: that the body handles conduct complaint cases AND investigates criminal cases concerning police personnel, prosecutors, other police and prosecution personnel performing police or law-enforcement tasks, and defence personnel assisting the police; that it initiates investigations where a person has died or been seriously injured as a result of police intervention or in police custody; that it "is independent of both the police and the prosecution service"; that it is governed by the Police Complaints Council, its supreme governing body, chaired by a High Court judge, with day-to-day management by a chief executive and around 40 staff; and that its legal basis is Act no. 404 of 21 April 2010 (in force 1 January 2012) and Act no. 1172 of 8 June 2021 (in force 1 July 2021 and 1 January 2022), with the provisions carried in the Administration of Justice Act. Note for translation integrity: the body’s own English name is "the Police Complaints Authority", without the "Uafhængige" (independent) that its Danish name carries. Whether it holds prosecuting authority was NOT established and is not claimed.
E4J University Module Series — Crime Prevention and Criminal Justice, Module 5 (Police Accountability, Integrity and Oversight), Topic 2: Key mechanisms and actors in police accountability and oversight
United Nations Office on Drugs and Crime (Education for Justice) · International organisation · link verified 2026-08-10
The UNODC teaching module on police accountability mechanisms, read directly. Supports UNODC's own conceptual framework of accountability 'before, during and after the act' (ex-ante, ongoing and ex-post oversight); that internal control within the police service is the first degree of control in any police accountability system and works both preventively and reactively; that legal provisions alone are often insufficient for the day-to-day exercise of police powers, so services need comprehensive professional standards and codes of conduct giving practical guidance — the module's own worked example is guidance on arrest and detention procedures; and that because officers hold wide discretion and meet ethical dilemmas (the module instances bending laws for perceived greater law-enforcement objectives, and deceptive interrogation tactics used to extract a confession) services also need a code of ethics built on impartiality, fairness, equality, justice and honesty. Describes how accountability systems are DESIGNED. It does not establish that any particular system works, and no effectiveness or public-trust claim on this platform rests on it.