Sorry, you need to enable JavaScript to visit this website.


Authorised Professional Practice

This page is from APP, the official source of professional practice for policing.

First published
Written by College of Policing
Civil contingencies
6 mins read

In most cases where a major incident occurs, a police investigation commences to establish whether any crimes have been committed and, if so, by whom.

Role of the police

If it is clear that criminality is the cause of the incident, the police lead any investigations. Support may be required from specialist investigators from other agencies.

Where the cause is not immediately identifiable, the police follow standard procedures to preserve continuity of evidence. If there is no criminal activity, this assists industry-specific investigators when they arrive on the scene.

The police may be asked to assist with investigations carried out by specialists.

For further information see other investigating bodies

Role of the coroner

Where a fatality occurs in England and Wales, the coroner in whose jurisdiction the body lies takes possession of the body.

No activity, including movement of the body, can occur without the authority of the coroner.

In the event of a mass fatality incident – or an incident resulting in deaths over several jurisdictions from the same or similar causes – the chief coroner can appoint a single lead coroner for the coronial investigation.


The coroner must hold an inquest into the death of a person whose body lies in their jurisdiction if the:

  • cause of death is unknown
  • death was violent or unnatural
  • death occurred in custody

The purpose of the inquest is to determine who the person is, how, when and where they died, and the circumstances around their death.

An inquest is opened and adjourned to allow the release of the body to the family. Where a criminal investigation is conducted, the coroner may accept the findings of the criminal investigation and close the case without resuming the inquest. The coroner will take the family’s wishes into account when making this decision.

Death of foreign military personnel

Where the death of foreign military personnel occurs, a foreign nation may wish to deal with their own dead. The coroner can pass jurisdiction to the Lord Chancellor (acting for the Ministry of Justice) to make a decision as to whether jurisdiction passes on again to the foreign nation under the Visiting Forces Act 1952.

Once jurisdiction is passed to the Lord Chancellor for consideration, the body of the deceased is no longer under the jurisdiction of the coroner and cannot legally be moved. The body should, therefore, be removed to a hospital mortuary before the coroner passes jurisdiction to the Lord Chancellor, as the decision process may take several days. This is to maintain dignity for the deceased and to prevent delay in investigation and establishing identity.

Other investigating bodies

The police may be asked to assist with investigations carried out by specialists.

Rail Accident Investigation Branch

The Rail Accident Investigation Branch (RAIB) is the UK’s independent body for investigating accidents and incidents that take place on the railways of Great Britain and Northern Ireland, and tramways in England and Wales.

RAIB is not a prosecuting body, and it does not apportion blame or liability. Investigations focus solely on improving safety. Breaches of legislation are dealt with by other organisations, usually the police and safety authorities.

The RAIB aims to improve the safety of the railways by:

  • carrying out investigations to determine the causes and circumstances of railway accidents and incidents
  • identifying any other factors that contributed to the event or made the outcome worse
  • publishing investigation reports containing details of the investigation
  • making evidence-based safety recommendations to reduce the likelihood of reoccurrence
  • increasing awareness of how railway accidents happen through effective liaison and discussion and by disseminating intelligence from investigation initiatives
  • improving national and international cooperation in railway accident investigations

For further information see Rail Accident Investigation Branch.

Office of Rail Regulation

The Office of Rail and Road (ORR) is the:

  • economic regulator for railway infrastructure (Network Rail and High Speed 1 Ltd)
  • health and safety regulator for the rail industry as a whole, including mainline, metro, tramways and heritage railways across Britain
  • industry’s consumer and competition authority

Where the RAIB and/or the police are also conducting an investigation, ORR activities should be limited to:

  • establishing whether there has been a significant breach of health and safety law
  • providing any necessary advice to the RAIB, the British Transport Police, the Home Office police forces, the Police Service of Northern Ireland (PSNI) or Police Scotland

For further information see Office of Rail and Road.

Air Accidents Investigation Branch

The UK Air Accidents Investigation Branch (AAIB) is part of the Department for Transport, and is responsible for investigating civil aircraft accidents and serious incidents within the UK and its overseas territories. The Chief Inspector of Air Accidents reports directly to the Secretary of State for Transport.

The fundamental purpose of AAIB investigations is to determine the circumstances and causes of accidents, with a view to preserving life and avoiding accidents in the future. It is not to apportion blame or liability.

For further information see:

Ministry of Defence

The Ministry of Defence (MOD) is responsible for investigating military air accidents. This is done through a Board of Inquiry.

An MOD investigating officer (military operational commander) usually attends the scene and a Royal Air Force liaison officer represents the MOD at the strategic commanders meeting.

Sometimes, the AAIB may also investigate accidents involving military aircraft – see The Civil Aviation (Investigation of Air Accidents and Incidents) Regulations 2018.

The MOD also supports the AAIB on request with non-military air crashes.

Marine Accident Investigation Branch

The Marine Accident Investigation Branch (MAIB) examines and investigates all types of marine accidents to – or on board – UK ships worldwide, in addition to other ships in UK territorial waters.

To fulfil its primary role of improving safety of life at sea, it is essential that MAIB investigates accidents immediately, before vital evidence decays, is removed or lost.

To enable this, the law requires that accidents (including serious injuries) be reported by the quickest means possible.

For further information see Marine Accident Investigation Branch.

Health and Safety Executive

The Health and Safety Executive (HSE) aims to reduce work-related death, injury and ill health. Its activities include investigating incidents, enquiring into citizens’ complaints and enforcing the law.

HSE prosecutes both companies and individuals for breaches of health and safety law. The HSE and police may conduct a joint investigation. Primacy may shift between the two as the investigation proceeds.

For further information see Health and Safety Executive.

Was this page useful?

Do not provide personal information such as your name or email address in the feedback form. Read our privacy policy for more information on how we use this data

What is the reason for your answer?
I couldn't find what I was looking for
The information wasn't relevant to me
The information is too complicated