Accessing protected AIB material in a criminal trial

 ORR and Dorris v Secretary of State for Transport [2023] EWCR 1 (judgment here)

This judgment, that was held back until the completion of a criminal trial, highlights again the thorny issue of the disclosure into subsequent legal proceedings of ‘protected material’ that has been collected during an independent Accident Investigation Branch’s (‘AIB’) investigation.

Limited and proportionate disclosure of protected Rail Accident Investigation Branch (‘RAIB’) material was ordered for this criminal trial to permit the relevant experts to comply with their oaths to tell the jury the whole truth, and not be inhibited in doing so.  The disclosure was extremely circumscribed and limited to that strictly necessary for a fair trial.

Notably this prosecution came after the inquest into the seven deaths in the Croydon ‘Sandilands’ tram crash and as such the decision does not make any inroads into the position in coroner’s courts, where deference to the AIB as the body with the greatest expertise will continue to mean that a coroner will generally not be permitted access to AIB material to investigate the cause of a fatal incident for themself.

The application

In the course of a criminal trial the Office of Rail and Road (‘ORR’) sought an order for disclosure of some expert reports, that came into existence as part of the investigation by the Rail Accident Investigation Branch (‘RAIB’) into the Croydon ‘Sandilands’ tram crash in November 2016.

As with all AIB material, the reports were protected from disclosure without an order of the High Court by reason both EU directives and English Regulations.[1]

The overall purpose of the protection of such material is to enable the AIBs to properly and fully investigate fatal accidents, with the aim of preventing whatever happened that led to the accident in question. This ‘lessons learned’ priority and approach to these important investigations, by necessity, requires the fullest possible amount of information gathering, with participants in the investigation protected by anonymity when sharing any information and opinions with the AIB. The information given remains confidential beyond what is published in the AIB’s report.   The material collected in the course of AIB investigations is therefore protected by both national law and international conventions.  It is considered ‘protected material’ that will not be disclosed to anyone for any purpose without an order of the High Court.   A breach of those disclosure obligations amounts to a criminal offence.

The history of proceedings

The RAIB investigated the Sandilands tram crash and published their report in 2017. The Crown Prosecution Service (‘CPS’) had decided by October 2019 not to prosecute any of Transport for London (‘TfL’), Tram Operations Ltd (‘TOL’) or the driver, Mr Dorris, with corporate manslaughter, gross negligence manslaughter or any other of the more serious offences which are within the remit of the CPS to consider.

At the end of a nine week inquest in 2021 the jury rejected a finding of unlawful killing and returned a narrative conclusion incorporating accidental death in respect of each of the seven fatalities. Subsequently, in early 2022, the ORR decided to charge TfL, TOL and Mr Dorris with health and safety offences.  TfL and TOL pleaded guilty (and have now been fined £14m for failing in their health and safety duties), but Mr Dorris faced a Crown Court trial.

Disclosure for the trial

An expert report had been prepared by Professor Wann, a psychologist and visual effects expert, for the British Transport Police (‘BTP’) to aid the prosecution.  Prof Wann had earlier been involved in assisting the RAIB and so he had been permitted to have access to evidence and information that was protected material under the Regulations.  In 2017 he had visited the location, taken measurements and other details, and prepared a detailed analysis. This process had led to the creation of two draft documents for the RAIB which were protected under the regulations.  These documents were drawn upon, but were not fully replicated, in the report that Prof Wann provided to BTP for the criminal trial.

This protected material was effectively earlier and more fuller and detailed versions the expert opinion provided to the BTP, without which it would be difficult – if not impossible – for Professor Wann to comply with his duties as an expert in criminal proceedings, particularly given the years that had now passed since he had conducted his investigation.   Understandably, given the complexity of the law around this topic, and aware of his overriding duties to the court, the expert did not recall or not appreciate the constraints on the protected material and so shared his earlier reports with the prosecution.   A few days before trial those reports were also disclosed to the defence. It was only when the RAIB became aware of this that the protected status of the material and the difficulty this created was realised.

Equality of arms between parties, and particularly experts, meant that it was important for the defence expert to be permitted to consider Prof Wann’s earlier reports. Indeed the defence expert had already been given those documents before the difficulty with him seeing them was recognised.

The practical, but short term, solution arrived at (after involving the RAIB), was for the court to make order that permitted disclosure only for the purposes of the experts’ meeting, with the defence expert giving confidentiality undertakings.   However it was obvious that some of the contents of Professor Wann’s earlier work may need to be referred to in open court during the trial the course of cross examination. In the interests of a fair trial for the defendant, reference to the protected material was likely to be required.

The decision

The judge noted that strong policy considerations lay behind the legislative scheme in this area: disclosure of protected material could have a significant and adverse domestic and international impact on future safety investigations. There was an important public interest in those who provide full and frank information to AIB investigators knowing that such material would be kept confidential.

The principle to be applied was that derived from Norfolk and the various Shoreham Aircrash judgments:[2]

Whether the benefits of disclosure outweigh the adverse domestic and international impact that such action may have on that or any future safety investigation

The competing public interest in the effective investigation and detection of crime, in the defendant having a fair trial, and in the experts being able to comply with their duties to the court and to give their truthful evidence all pointed towards an order allowing the protected material to be referred to at trial.

The judge determimed that, on the facts specific to this case, the balancing exercise was somewhat more substantially weighted towards disclosure than it might be in other cases.  An order was made limited to that material strictly necessary so that the experts could be uninhibited in giving their evidence and being examined about their opinions.

In due course Mr Dorris was acquitted by the jury by an unanimous verdict on 19 June 2023.


That disclosure was permitted in this case must be seen in the context of criminal proceedings where the interests of justice in holding a fair trial will, rightly, weigh very heavy when someone’s liberty may be at stake.

As coroners will be aware following the Norfolk[3] and the Shoreham Aircrash ‘Sussex’[4] cases, the coroners’ statutory duty to investigate fatal accidents will generally not justify disclosure of protected AIB material for the purpose of an inquest.  Rather the coroner will be expected to defer to the views of the AIB inspectors, who have by far the greatest expertise in investigating the cause of a fatal crash, and accept the AIB findings unless there is some clear flaw or inadequacy in their investigation.   Importantly, even the general words of Schedule 5 CJA 2009 cannot override the specific legislation governing the important protection of material derived from the investigation of accidents by the AIBs.


[1] Railways and Transport Safety Act 2005, EU Directive 2004/49/EC and the Railways (Accident Investigation and Reporting) Regulations 2005.

[2] Chief Constable of Sussex Police v Secretary of State for Transport, British Airline Pilots Association [2016] EWHC 2280 (QB), and BBC v Secretary of State for Transport [2019] EWHC 135 (QB).

[3] R (Secretary of State) v HM Senior Coroner for Norfolk & another [2016] EWHC 2279 (Admin)

[4] HM Senior Coroner for West Sussex v Chief Constable of Sussex Police & others [2022] EWHC 215 (QB