The coronial framework
Under the Coroners and Justice Act 2009 and the Coroners (Investigations) Regulations 2013, the coroner is the statutory officer responsible for investigating unexpected deaths in England and Wales. Every unexpected hospital death is, in principle, a coronial matter. The coroner has statutory powers to: order post-mortem examination; commission toxicological and histological analysis; take sworn witness evidence; and make findings on cause of death and the circumstances surrounding it.
Where a coroner suspects a death may have been caused by an unlawful act, they have an obligation to refer to the police. The coronial-police interface is the institutional gateway between routine-death investigation and criminal investigation.
What the framework required at the Countess of Chester
Each unexpected neonatal death on the unit from June 2015 onwards should have triggered coronial investigation. In practice:
- Most deaths were referred to the coroner for post-mortem determination of cause of death.
- Post-mortems were performed by hospital pathologists, not forensic pathologists, because the deaths were not at the time categorised as suspected crime.
- The coroner had powers to order more extensive investigation (forensic post-mortem, toxicology, imaging) but did not exercise them because the cluster had not been escalated to that level.
- The Trust executive team’s framing of the cluster as a service-level rather than criminal concern (through 2016) influenced the coronial posture.
What a proper coronial process would have produced
If, from the first consultants’ concerns in July 2015, the cluster had been referred to coronial investigation as a suspected-crime cluster, the coroner would have had the following tools available:
- Forensic post-mortem. Home Office pathologists, full-body post-mortem imaging, systematic histological sampling, toxicological screen.
- Sample retention. Physical exhibits — tubes, catheters, TPN bags — would have been sequestered.
- Chain of custody. Forensic chain-of-custody documentation from the outset.
- Blinded review. Independent pathology review by a second forensic pathologist, blinded to any suspect hypothesis.
- Inquest. Sworn witness evidence in open court, with legal representation for interested parties.
- Police referral. If post-mortem or investigation disclosed suspicious features, direct referral to police under the coronial-police interface — with forensic-standard evidence already collected.
What happened instead
The cluster was not referred to coronial investigation as a suspected-crime cluster at the time. The Trust executive team managed the response through internal review, external service-level review (RCPCH, CQC, NHS Improvement), and HR process. By the time Operation Hummingbird opened in May 2017, most coronial-forensic steps that could have been taken at the time of the deaths were no longer available.
The criminal trial in 2022–2023 therefore proceeded on evidence that had been developed under the clinical-post-mortem framework, not the forensic-post-mortem framework. The Crown’s causation expert, Dr Dewi Evans, worked from clinical records rather than from forensic-standard evidence.
The Sir James Jones review
Post-Letby, the senior coroner for Chester and Cheshire West instructed an additional review of the coronial handling of the deaths. Public commentary by senior coroners and coronial-law specialists has addressed the structural question: should coroners have a statutory duty to open formal coronial investigations into apparent clusters of unexpected deaths at the same institution? This is now an active UK coronial-law reform question, flowing partly from the Countess of Chester experience.
Why this matters for the CCRC review
The CCRC, in assessing the safety of the Letby convictions, can consider the forensic-evidence gap the non-coronial pathway produced. A conviction on clinical- post-mortem evidence, without the forensic-standard evidence a proper coronial process would have produced, is a conviction on a thinner evidential base than appellate review would normally expect. Combined with the expert-disagreement ground under the Cannings principle, the forensic-gap ground contributes to the overall unsafety assessment.