Why his position matters
Lord Sumption is, by professional standing, one of the most senior retired English judges still in public life. He sat on the Supreme Court from 2012 to 2018, appointed directly from the Bar. Before that he was, for three decades, one of the leading senior advocates in the English Bar. His professional default is careful, procedurally conservative, and cautious about second-guessing jury verdicts.
It is precisely that professional default that makes his 2025 intervention load-bearing. When a former Supreme Court Justice — whose public writing has consistently cautioned against judicial overreach and the erosion of democratic institutions — publicly calls for a case to be re-examined, that call is not the sound of a campaigner speaking. It is the sound of an institutional-insider concern.
Professional background
- Justice of the Supreme Court of the United Kingdom, 2012–2018, appointed directly from the Bar — the first barrister in modern times to be appointed to the court without previously holding a full-time judicial office.
- King’s Counsel; previously one of the leading senior commercial and public-law advocates of his generation.
- Historian. Author of a multi-volume history of the Hundred Years War and other works of mediaeval history. Fellow of the Royal Society of Literature and the Society of Antiquaries.
- 2019 BBC Reith Lecturer on “Law’s Expanding Empire”, a five-lecture series on the relationship between law, politics and democratic institutions.
- Regular broadsheet columnist since leaving the Court; author of Trials of the State (2019) on the same themes.
His position on the Letby evidence
In late-2025 broadsheet interventions and follow-up interviews to the Reith Lectures material, Lord Sumption addressed the Letby case specifically. The substance of his position can be reduced to three points:
- The body of expert evidence now in the public domain is materially different from what was before the jury in 2023. When such a shift occurs, the criminal justice system has a mechanism designed to examine whether the conviction is still safe. That mechanism is the CCRC.
- The statistical arguments presented to the jury are of a type that the Royal Statistical Society’s post-Sally-Clark framework has explicitly warned against. That framework exists because previous miscarriages of justice proceeded on the same pattern of reasoning.
- Public confidence in the criminal justice system is better served by transparent re-examination of a disputed conviction than by defence of a verdict against a tide of independent expert opinion. That is not a campaigner’s position; it is a system-stability position.
Why this is different from most public commentary
Public commentary from a sitting or recently-retired judge on a specific conviction is constitutionally unusual. Judges typically avoid it for good reasons: the appeal system exists and extra-judicial commentary risks interfering with it. That Lord Sumption has chosen to speak, despite the professional convention against it, is itself a signal that he considers the usual calculus — wait, let the appeal process run, do not say anything — to be outweighed by the specific features of this case.