How the Clark / Cannings / de Berk / Anthony precedents apply operationally
Prosecution claim
The Clark, Cannings, Anthony and de Berk miscarriage-of-justice cases concerned specific sets of facts different from the Letby case. The precedents are not controlling on Letby on their specific facts.
Counter-evidence
The precedents apply not on their specific facts but on the legal principles they established. The Royal Statistical Society's post-Clark framework (2001) is the canonical UK reference on statistical evidence in criminal trials — applicable to any statistical-evidence case, including the Letby shift-rota chart. The Cannings principle (2003) is the operative Court of Appeal test on disputed medical expert evidence — applicable to the Letby expert-disagreement record. The de Berk statistical critique framework (Dutch Supreme Court 2010) is internationally available analytical scaffolding — applied to Letby by Prof. Richard Gill himself. The Anthony CCRC-referral precedent (2005) establishes the procedural route the Letby application is following. Each of these precedents operates at the level of principle, not specific fact — which is how legal precedent works.
Precedents apply at the level of principle. The Cannings principle says a conviction on disputed medical expert evidence is unsafe. The Letby expert record is a record of disputed medical expert evidence. The principle therefore applies.
What the jury heard
The jury does not receive legal precedent; that is a matter for the judge's directions and for appellate review. The precedent-application question is therefore a CCRC / Court of Appeal question, not a jury question.
What the Panel says
The Panel addresses the medical-evidence content. The legal-precedent application is a separate layer that flows from the Panel's medical findings: if the medical evidence is disputed at the level the Panel documents, the Cannings principle is engaged.
What independent experts add
- Clark established the RSS statistical framework.
- Cannings established the disputed-medical-evidence principle.
- Anthony established the CCRC-referral procedural route.
- de Berk established the international statistical-critique framework (Gill).
- Sally Clark's case drove the 2003 Attorney General's review of 297 similar convictions.
- Together, the precedents form a framework for reviewing post-conviction expert-evidence cases.
- The Letby October 2025 CCRC application operationalises this framework.