Context
In October 2025 Lucy Letby’s legal team, led by Mark McDonald KC, filed a formal application to the Criminal Cases Review Commission seeking referral of the 2023 convictions and the 2024 Child K retrial conviction back to the Court of Appeal. The application is accompanied by more than thirty-one independent expert reports. This is the defining legal event of the post-conviction phase of the case.
The statutory test
The CCRC, under section 13 of the Criminal Appeal Act 1995, may refer a conviction to the Court of Appeal where, in its view, there is a “real possibility” that the Court of Appeal would not uphold the conviction. “Real possibility” is a lower threshold than “probability”. It exists specifically to allow referral where new evidence exists that the original court did not have.
The October 2025 application asks the Commission to be satisfied that the expert reports filed with it constitute such new evidence, and that it creates a real possibility of the Court of Appeal quashing the convictions.
What the thirty-one reports cover
- Neonatology. The Shoo Lee International Expert Panel report (Feb 2025) and affiliated specialist reports on each indicted case.
- Paediatric pathology. Independent re-reading of post-mortem findings in the cases where pathology was material.
- Clinical biochemistry. Joint Expert Witness Insulin Report on Babies F and L.
- Physiological modelling. Prof. Geoff Chase’s work on insulin-value plausibility.
- Statistics. Prof. Richard Gill and Prof. Peter Green’s reports on selection bias and the post-Sally-Clark framework.
- Infectious disease. Reports on the documented superbug outbreak and its implications for natural-causes explanations of the cluster.
- Post-mortem radiology. Review of the absence of intravascular gas on imaging that would be expected if air embolism had occurred.
McDonald KC’s public framing
Mark McDonald KC
This is not a re-analysis of the same evidence a jury heard. This is a body of independent expert evidence, compiled by specialists whose professional standing is beyond serious dispute, which the jury did not have. The CCRC exists for cases of this character. We ask the Commission to examine it with the urgency the issue deserves.
What happens next
The Commission will now consider the application. There is no statutory deadline. In practice, applications of comparable complexity have taken between 18 months and several years. A referral, if made, does not itself overturn the conviction; it triggers a fresh hearing at the Court of Appeal. The Court of Appeal can quash, uphold, or order a retrial.
Read alongside
CCRC review explained, Mark McDonald KC — biography, Where the evidence now stands, Panel press conference.