Lucy Letby v R

Limited research and rare direct clinical experience do not, without more, make expert evidence about neonatal air embolus inadmissible. A properly qualified clinician may give evidence on its causes, mechanism and signs. The jury may assess a diagnosis based on a combination of findings consistent with air embolus, exclusion of realistic alternatives and other circumstantial evidence; no single sign need be diagnostic.

For no case to answer, questions of reliability and weight remain for the jury where the evidence, taken at its highest, could support conviction. A jury deciding murder or attempted murder need be sure of the deliberate harmful act, intent and causation, but need not agree the precise mechanism or evidential route unless disagreement would concern an essential ingredient or a different defence. Fresh expert evidence on appeal is not admitted where it could have been called at trial without a reasonable explanation and does not address the prosecution’s actual case.

The applicant was convicted at Manchester Crown Court before Goss J and a jury of seven murders and seven attempted murders of babies. She received life sentences with whole life orders. A single judge refused leave to appeal, and she renewed her application on four grounds concerning expert evidence, the submission of no case to answer, the direction on the precise harmful acts, and a possible jury irregularity. She also sought to adduce fresh expert evidence and to add a further ground concerning the diagnosis of neonatal air embolus. The central issues were whether the prosecution evidence was admissible and sufficient, whether the jury had to agree the precise mechanism of harm, whether the fresh evidence met the statutory conditions, and whether the judge had properly investigated the alleged jury irregularity.

1. Disposition. The renewed application for leave to appeal against conviction, the application to vary the grounds and the application to adduce fresh evidence were refused. None of the grounds was arguable.
2. Expert evidence. The rarity of neonatal air embolus, limited literature and limited direct clinical experience did not prevent qualified clinicians from giving relevant expert evidence. Experienced neonatologists and other specialists could address its causes, biological mechanism, consequences and possible signs. Dr Evans had sufficient expertise, and his investigative role did not prevent him from acting as an independent expert. Allegations about his manner, reliability and impartiality were matters for the jury. The judge was also entitled to refuse exclusion under section 78 of the Police and Criminal Evidence Act 1998.
3. No case to answer. Applying the approach in R v Galbraith (1981) 73 Cr. App. R. 124, the evidence was capable of supporting a conviction. The experts did not diagnose air embolus from skin discolouration alone. They relied on a combination of findings, including sudden collapse, unusual colour changes, unsuccessful resuscitation, exclusion of realistic alternatives and other expert and circumstantial evidence. The reliability and weight of that evidence were for the jury.
4. Precise harmful act and jury unanimity. The distinction in R v Ames [2023] EWCA Crim 1463, and the principles concerning a Brown direction, applied. The jury had to be sure that the applicant deliberately committed an unlawful act or acts, with the requisite intent and causation, but did not have to agree the precise mechanism or evidential route. A direction requiring unanimity on the precise act was necessary only where disagreement would amount to disagreement about an essential ingredient, distinct events constituting that ingredient, or means giving rise to different defences.
5. Fresh evidence. Under section 23 of the Criminal Appeal Act 1968, the proposed evidence was not received. It could have been obtained and called at trial, no reasonable explanation for the omission was shown, and it addressed a mistaken premise because the prosecution experts had not diagnosed air embolus solely from skin discolouration.
6. Jury irregularity. The investigation was a case-management decision for the trial judge. There was no obligation to conduct a mini-trial by calling the complainant where the material already available reliably resolved the issue. The judge was entitled to rely on the juror’s answers, his own observations, the inconsistencies in the complaint and the length and character of the jury’s deliberations.

1. Court of Appeal (Criminal Division). On 2 July 2024, the court refused the renewed application for leave to appeal and all associated applications: [2024] EWCA Crim 748.
2. Single judge. Sir Robin Spencer refused leave to appeal, following which the applicant renewed the application.
3. Manchester Crown Court. Before Goss J and a jury, the applicant was convicted of seven murders and seven attempted murders and sentenced to life imprisonment with whole life orders.