Major investigation and public protection

Major incident room standardised administrative procedures (MIRSAP)

ACPO (2005) Guidance on Major Incident Room Standardised Administrative Procedures (MIRSAP)

This document is currently under review and the link will be updated as soon as the new MIRSAP manual is available.

What is MIRSAP?

The major incident room standardised administrative procedures (MIRSAP) were introduced alongside the Home Office large major enquiry system (HOLMES), following the 1981 publication of the Byford report into the Yorkshire Ripper investigation. The report highlighted that the single most important lesson from this investigation was the need for standardisation of procedures in major incident rooms (MIRs). MIRSAP supports the management and sharing of information within and across forces in large and complex major investigations, enabling timely actions to be taken and reducing the risk of information being lost or misinterpreted.

Lord Byford said:

‘[…] a member of any police force with experience of major incident room work should be able to go to a major incident room in another force and immediately know the location and contents of indexes and records and the management structure of any inquiry.’

The procedures set out in a MIRSAP manual can be adapted to suit the specific size and needs of an investigation. The manual also supports local decision-making around roles and responsibilities, structure, information management and associated risks. It does not direct or mandate a specific process or course of action. MIRSAP provides advice for the establishment, resourcing and running of an effective MIR for:

  • senior investigating officers (SIOs)
  • senior managers
  • MIR staff
  • those carrying out inspections or reviews

MIR responsibilities

  • Providing the SIO with an accurate record of all relevant information relating to the investigation, together with the enquiries made and results obtained.
  • Showing the state of the investigation and how much work (outstanding actions) remains to be done at any time.
  • Enabling investigators that make enquiries to establish whether any person has previously come to notice in the investigation.
  • Providing investigators with a means of acquiring all the knowledge that the investigation already has about their enquiry subjects.
  • Keeping records that highlight people, vehicles or other factors that have become subject to enquiry, so that those records can pinpoint individuals for further investigation.
  • Acting as a means of historical reference so that, in long-running enquiries, officers joining the investigation can have easy reference to major policy decisions and the rationale behind them.
  • Facilitating the production of comprehensive reports for legal consideration.
  • Recording and linking all information so that it may be readily retrieved to aid the SIO and their team to establish priorities. This will ensure that all enquiries are made efficiently and that the results are analysed.
  • Ensuring all the recognised protocols have been applied so that the necessary research can be made across different databases and, where appropriate, investigations can be linked.
  • Maintaining the database from which it is possible to undertake internal and external reviews.

Page last accessed 21 October 2021