Major Incident Room Standardised Administrative Procedures (MIRSAP)
Major Investigation and Public Protection — Authorised Professional Practice
Summary
Major Incident Room Standardised Administrative Procedures (MIRSAP) were established to improve the management and sharing of information during complex investigations, following the Byford report's recommendations after the Yorkshire Ripper case. MIRSAP allows police forces to standardize processes in Major Incident Rooms (MIRs), ensuring that any experienced officer can easily adapt to different major incident environments. The MIRSAP manual provides guidelines tailored to varying investigation scales, supporting local decision-making regarding roles, structure, and information management. Responsibilities of MIRs include maintaining accurate records of investigations and facilitating efficient information retrieval to aid senior investigating officers (SIOs) in establishing priorities for enquiries.
Key principles
- 1Standardization of procedures across police forces
- 2Support for information management in complex investigations
- 3Facilitation of timely decision-making and action
- 4Flexibility to adapt procedures to specific investigation needs
- 5Accountability and historical records of major policy decisions
Defined terms
- MIRSAP
- Major Incident Room Standardised Administrative Procedures
- SIO
- Senior Investigating Officer
- MIR
- Major Incident Room
Full guidance
Major incident room standardised administrative procedures (MIRSAP)
Responding to public protection and major investigation issues, for example, child abuse, knife crime and sexual offences
This page is from APP, the official source of professional practice for policing.
See also the National Police Chiefs' Council (NPCC) (2021) Guidance on Major Incident Room Standardised Administrative Procedures (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(opens an external website in the same tab) 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.
> \[…\] 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. > > **Lord Byford**
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
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.
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Read the full APP guidanceSource: College of Policing — Authorised Professional Practice · Crown copyright, licensed under Open Government Licence v3.0. Summary fetched 2026-06-27.