Why he matters in this case
Dr Shoo Lee is the single most consequential expert figure in the post-conviction review of the Lucy Letby case. Three things make that so.
First, he is the co-author of the 1989 paper that the Crown’s lead expert cited as authority for the diagnosis of neonatal air embolism. That paper — Lee & Tanswell, “Pulmonary vascular air embolism in the newborn”, Archives of Disease in Childhood 1989 — is the foundation of the diagnostic framework the prosecution used. Dr Lee has since publicly stated, in clear terms, that the skin signs described at the Letby trial do not match the findings in his paper and that his work was misapplied.
Second, having reached that view, he did not simply say so in a letter. He convened an international panel of fourteen senior neonatologists and paediatric specialists from Canada, the United Kingdom, Sweden, Germany, Belgium, New Zealand, Taiwan and the United States, and had them independently review the medical evidence for every count on the Letby indictment. The Panel’s unanimous view, announced at a London press conference on 3 February 2025, was that there is no medical evidence of deliberate harm in any of the cases reviewed.
Third, his professional standing makes it extremely difficult to characterise the Panel’s findings as fringe. He is not a campaigner. He is the leading Canadian authority on neonatology, a former Paediatrician-in-Chief at one of the largest teaching hospitals in North America, and Professor Emeritus at one of the world’s leading medical schools.
Professional background
- Professor Emeritus of Paediatrics, University of Toronto.
- Former Paediatrician-in-Chief, Mount Sinai Hospital, Toronto.
- Founding Director of the Canadian Neonatal Network and the Canadian Preterm Birth Network — national quality-improvement collaboratives that have been used as models internationally.
- His research career has focused on quality improvement in neonatal intensive care, population-level outcomes for preterm infants, and (earlier) the pathophysiology of neonatal circulatory collapse — including the 1989 air-embolism paper now central to this case.
The 1989 paper
The paper in question — Lee & Tanswell, “Pulmonary vascular air embolism in the newborn”, Arch Dis Child 1989 — describes a specific pattern of skin discolouration seen in infants with large-vessel air obstruction. The Crown’s expert at the Letby trial presented skin-discolouration photographs from several cases as matching the 1989 criteria. Dr Lee, reviewing the photographs and the descriptions given at trial, disagrees: the pattern described at trial is a non-specific mottling of the kind produced by any severe circulatory compromise (sepsis, shock, cardiac decompensation), and does not match the migrating bright-pink-against-pallor pattern that the 1989 paper actually describes.
His phrasing at the London press conference was unusually direct for a senior academic: he said his work had been misapplied.
The International Expert Panel (2024–2025)
From mid-2024, Dr Lee convened a panel of fourteen senior neonatologists and paediatric specialists. Panel members are listed in full on our Experts page and include Dr Neena Modi (Imperial College London, past president of the Royal College of Paediatrics and Child Health), Dr Mikael Norman (Karolinska Institutet), Dr Helmut Hummler (Ulm), Dr Karel Allegaert (KU Leuven), Dr Prakesh Shah (Toronto), Dr Brian Darlow (Otago), and colleagues in the United Kingdom and the United States.
The panel reviewed the medical evidence case by case, using the contemporaneous medical records and post-mortem findings. Its report — hosted by the defence team at lucyletbyinnocence.com — concluded that every deterioration and every death is explicable by natural causes or by identifiable sub-optimal clinical care. No case met the diagnostic criteria for deliberate harm.