Policy paper

Memorandum of Understanding between The Crown Prosecution Service and the Air, Marine and Rail Accident Investigation Branches

Published 23 October 2008

1. Introduction

1. This Memorandum of Understanding (MOU) is established between the Crown Prosecution Service (CPS) and the Air, Marine and Rail Accident Investigation Branches (AIBs). When developing common policy or joint external agreements, the three AIBs coordinate their activities through the Accident Investigation Chiefs’ Council (AICC), which comprises the three Chief Inspectors and a non-executive Chair. This MOU has been developed by the AICC. Annex A contains details about the participants in this MOU and the AICC.

2. This MOU is not legally binding. The three AIBs each have a separate legal regime and some of the differences between them are referred to in this MOU. The participants understand that its aim is to create practical working arrangements between the AIBs and the CPS. The specific legal regime of each AIB must still be respected.

3. The AIBs have a duty to conduct safety investigations into accidents in their respective transport sectors without apportioning blame or liability. Where there is evidence that an offence has been committed and it meets the Full Code Test in the Code for Crown Prosecutors, the CPS has a duty to make sure that the right person is prosecuted for the right offence, and to bring offenders to justice wherever possible.

4. The objective of this MOU is to provide best practice guidance, to facilitate cooperation (while respecting the AIBs’ independence) and to set out the respective roles and responsibilities of the CPS and AIBs. The CPS and the AIBs will ensure that all staff in their organisation are familiar with this MoU.

2. Basic principles of co-operation

5. Safety investigations and criminal investigations into air, marine and rail accidents will proceed in parallel. The aim of this MOU is to ensure that both investigations can progress effectively and independently, while promoting cooperation where permitted.

6. The public interest requires that safety considerations are of paramount importance. This means that the interests of an AIB investigation (including consideration of the possible effects on future investigations) may sometimes take precedence over a criminal investigation. The ability of witnesses to talk openly and without delay to an accident investigator is fundamental to the operation of the AIBs, as is the protection of sensitive material from disclosure.

7. The participants in this MOU have an interest in the available evidence to support their separate and different purposes. In criminal proceedings, the CPS must consider whether evidence can be used in court and is reliable and credible, and ensure there is no other material that might affect the sufficiency of evidence. The AIBs will consider all requests from the CPS for specific items of evidence and factual information and will disclose such material where permitted by their respective legal regimes.

8. The CPS will inform the AIBs if they have an interest in a specific investigation and may request information and/or seek cooperation at any time.

3. The sharing of evidence/information

3.1 Protected evidence

9. Witnesses providing evidence to AIB investigations are afforded specific protections. The legislation for each of the AIBs differs in its detail (Annex B), but AIBs are prohibited from disclosing witness details, statements or declarations unless ordered to do so by the High Court^{[footnote 1]}.

10. A witness should always consult the relevant AIB before disclosing a statement to a third party. Generally, witness statements provided to the Air Accidents Investigation Branch (AAIB) cannot be disclosed in the absence of a court order, even with consent of the witness. If a witness to the event has provided a statement or declaration to the Marine Accident Investigation Branch (MAIB) or Rail Accident Investigation Branch (RAIB), he or she will be advised that they may share their statement or declaration with a third party if they wish. Nonetheless, it may be necessary for the AIB to insist on some redaction of material if the statement refers to material which is itself protected.

11. Where the AIBs are generally prohibited from disclosing information, its disclosure can be ordered by the High Court^{[footnote 1]} and ^{[footnote 2]}. The court is required to carry out a public interest balancing test between the benefits of disclosure in the interests of justice against the potential adverse impact it might have on the AIBs in conducting their current or future investigations.

3.2 Experts’ reports

12. An AIB may commission reports from experts on technical or other specialist matters relevant to its investigation. AAIB experts’ reports cannot be disclosed unless the High Court orders disclosure. The Chief Inspectors of the MAIB and RAIB can exercise discretion in deciding whether and when to share such material (if it has not already been published) with the CPS for any lawful purpose. They will normally do so unless disclosure would be prejudicial to an ongoing safety investigation or future investigations. Each case is considered on an individual basis. The guiding principle that will apply is whether such disclosure is likely to compromise the AIBs’ general aims of improving safety and preventing future accidents. Even when disclosure is possible, some redaction of protected material may still be necessary. When disclosure is subject to discretion, the AIB may take into account whether or not the final investigation report has been published. An expert should always consult the relevant AIB before making any disclosure of their report.

3.3 Non-protected factual information

13. The three AIBs may be able to share non-protected factual information obtained during an investigation upon request from other agencies investigating the same event. There are some differences between the regulations governing each of the AIBs that affect the detail of what technical and other evidence can be shared. Further details of disclosure limitations for the three AIBs are included in Annex B.

3.4 Interface between the AIBs and CPS on evidence

14. If the CPS has decided to prosecute, it should notify the relevant AIB^{[footnote 3]} indicating the basis of the prosecution. For each case, the CPS will appoint a designated person to communicate with the AIB. The designated person will identify material which the CPS wishes to obtain from the relevant AIB, noting any legislative requirements which pertain to the request. The AIBs will consider the request and outline the type(s) of evidence held that is/are relevant to the request from the CPS where legislation permits them to do so. Details of when the AIBs will be permitted to disclose information can be found at Annex B. If the requested evidence or information cannot be disclosed without an order from the High Court^{[footnote 1]}, the CPS will be advised accordingly. As the AIBs are prohibited from apportioning blame or liability, they cannot provide any advice to the CPS on the relevance of evidence held by the AIB to CPS cases. If deemed necessary, the CPS will submit an application to the High Court^{[footnote 1]} seeking disclosure of the evidence or information. The Court will consider the wider public interest in its determination of the case for disclosure. The CPS will endeavour to make any disclosure application in good time so that issues arising are resolved well in advance of the commencement of a criminal trial.

15. Information given to an AIB by the CPS will be treated as having been provided in-confidence if the AIB is requested to do so. For example, there may be prejudicial risks to ongoing criminal proceedings should CPS information be shared more widely. If an AIB identifies a reason for treating the information in any other way, they will initiate a discussion with the CPS to resolve the matter.

3.5 Destructive testing of evidence

16. To establish the cause of an accident, the AIBs may need to undertake tests that will modify the condition, dismantle or possibly destroy all or part of the physical evidence. At this often early stage in the investigation, the AIBs are likely to liaise with the Police (and if necessary, the CPS) concerning the actions to be taken. In recognition of the interest that the CPS may have in the handling of evidence, this MOU sets out the principles that will apply to such actions in Annex C.

4. Urgent safety actions

17. If, during an investigation, it is discovered that action needs to be taken to ensure that the transport system remains safe, the AIB will issue urgent safety advice^{[footnote 4]}, which may include Safety Recommendations. If the CPS had previously expressed an interest in an element of an AIB investigation that was directly associated with the subject of the advice, the CPS may be provided with a pre-publication version. The CPS will treat the document as confidential and will not disclose it before the date of publication. Any comments made by the CPS on timing of the publication of the advice will be considered, but the relevant AIB is not required to modify the timing of publication in response.

5. Action prior to the publication of the AIB report

18. The AIBs have a duty to publish reports on the accidents and incidents they investigate, as quickly as possible.

19. Before finalising a report, the AIB circulates a draft version to those parties specified in their respective regulations. The draft is confidential, and may not be disclosed by the recipient without permission from the respective AIB. The purpose of its circulation is to give those parties the opportunity to make representations to correct any factual discrepancies or to point out any relevant considerations that they believe have not been considered in the report.

20. Provided that the CPS has notified the AIB that they are considering whether to bring a prosecution or of its intention to prosecute, the AIB will give the CPS an opportunity to make representations regarding the timing of the publication of the final investigation report. In such circumstances, the AIB will make available to the CPS a pre-publication copy of the finalised report seven days before publication. The CPS will treat the pre-publication copy of the finalised report as confidential and will not disclose it before the date of publication.

21. Any representations made by the CPS on the timing of report publication will be considered. However, AIB Chief Inspectors must also consider the requirement to promulgate, without delay, lessons for the improvement of air, marine and rail safety. AIB reports may be published whether or not civil or criminal proceedings are in progress or planned, and the AIB is not required to modify the timing of the report.

6. The AIBs and criminal court proceedings

22. Although it is the AIBs’ preference that any prosecution take place after their investigation report has been published there may be valid reasons why a prosecution should commence before publication.

23. AIB investigation reports are published and freely available for anyone to read. However, AIB investigations are required to be independent of any judicial investigations or proceedings. AIB investigations are prohibited from apportioning blame or liability, and the AIBs consider that the investigation report is not therefore suitable for that purpose either. MAIB reports are inadmissible in any judicial proceedings whose purpose is to apportion blame or liability (civil or criminal) without an order from the High Court.

24. If requested, AIB inspectors will produce factual statements to describe their activities, such as investigation progress, continuity of evidence statements and the timing and content of tests they have conducted where they have had the effect of altering the state of evidence. This description of procedural steps will not include any opinion or analysis, because AIB inspectors are prohibited by regulation from including any opinion or analysis in such a statement (subject to order of the High Court^{[footnote 1]} and ^{[footnote 5]}).

25. The AIBs do not normally appear in criminal court proceedings because the court’s fundamental purpose is to apportion blame and/or liability, which the AIBs are explicitly prevented from doing by law. Therefore, the AIBs must not be put in a position where it could appear that they are supporting the apportionment of blame or liability. It must be made clear in court that any Inspector who appears is not appearing for either defence or prosecution, but to assist the court with the presentation of fact-based evidence.

7. Resolution of issues

26. Any disagreement between the CPS and the AAIB or MAIB about the practical application of this MOU that cannot be resolved locally will be referred to the Chief Inspector of the relevant AIB and the CPS Chief Crown Prosecutor/Head of Division. In the event of their absence, a designated deputy from within the respective AIB or the CPS may assume this responsibility.

27. For disputes involving the RAIB, if agreement cannot be reached the Chief Inspector will determine the course of action which best serves the public interest in accordance with sections 8(5) and (6) of the Railways and Transport Safety Act 2003, as amended. The Chief Inspector may only exercise this power where there is conflict with a RAIB investigation.

8. Review

28. The CPS and the AIBs will review the efficacy of this MOU every three years. Any of the participants may request a review of the provisions of this MOU (as signed 30 September 2020).

1. Crown Court or High Court for the RAIB. ↩ ↩² ↩³ ↩⁴ ↩⁵

2. RAIB regulations permit a witness to consent to disclosure of certain personal details and statement. They also give the Chief Inspector discretion to disclose some protected information, subject to the application of a public interest test by the court. ↩

3. The application should be made to the relevant Deputy Chief Inspector. ↩

4. The AIBs use different terms when issuing urgent safety material, and the term ‘advice’ (used by RAIB) embraces ‘information’ (used by AAIB) and ‘warning’ (used by MAIB). ↩

5. More information is available in Annex B - expert reports/inspector opinion and notes ↩