Why he matters in this case
Mark McDonald KC leads the legal team that replaced Lucy Letby’s trial counsel for the post-conviction stage. He is the public voice of the legal argument that the convictions are unsafe. His professional conduct of the case — coordinating the 31-plus independent expert reports, lodging the formal CCRC application, and responding to media enquiries — sets the procedural tempo of the CCRC review.
Professional background
- Criminal barrister; King’s Counsel. Known for appellate work involving contested expert evidence and miscarriage-of-justice cases.
- Lead counsel for Lucy Letby’s legal team in the post-conviction phase. Instructed after the May 2024 Court of Appeal refusal of leave to appeal.
- Public spokesperson for the defence side of the case in UK media during 2025 and 2026.
The CCRC application
The October 2025 CCRC application is the single most significant document in the current phase of the case. McDonald KC’s team filed it accompanied by more than thirty-one independent expert reports, covering:
- Neonatal medicine (the Shoo Lee Panel and affiliated specialists).
- Paediatric pathology.
- Clinical biochemistry and endocrinology (the insulin evidence — Adel Ismail and colleagues).
- Physiological modelling (Geoff Chase on insulin plausibility).
- Statistics (Richard Gill, Peter Green and the Royal Statistical Society framework).
- Infectious-disease and sepsis pathology.
- Post-mortem radiology.
The application asks the CCRC to refer the case back to the Court of Appeal on the statutory “real possibility” test — that, on the evidence now before the Commission, the Court of Appeal would quash the convictions.
What McDonald KC has said publicly
In press statements accompanying the application, McDonald KC has been careful to frame the argument as about the safety of the convictions, not the guilt or innocence of the defendant. His public line has consistently been:
- The weight-bearing medical evidence at trial has been comprehensively challenged by senior international specialists.
- The statistical evidence was structurally flawed in a way the Royal Statistical Society has itself described in published guidance.
- The post-conviction evidence is not re-analysis of the same facts — it is new expert evidence that the jury did not have.
- The CCRC exists precisely for cases of this character.