The comparison
| Evidential element | Beverley Allitt (1993) | Lucy Letby (2023) |
|---|---|---|
| Direct eyewitness to an act | Yes — colleague witnessed Allitt administering a drug | No — no witness to any alleged act of harm |
| Stolen physical evidence from unit | Yes — Allitt’s stolen Kardex (nursing record) recovered at her home | No — handover sheets recovered were professional work paperwork (see 257/21/236 ratio) |
| Contemporaneous physical-evidence chain | Yes — potassium and insulin vials / trace physical evidence | No — no physical-evidence recovery of any substance alleged to have been administered |
| Laboratory results: anomalous electrolytes | Yes — documented anomalous potassium values that could only be explained by exogenous administration | No — no electrolyte pattern matching the Clothier-style profile |
| Laboratory results: insulin evidence | Yes — insulin results produced at forensic-grade laboratory with confirmatory testing | Screening immunoassay at Royal Liverpool clinical biochemistry laboratory; no confirmatory mass spectrometry (see Guildford forensic-laboratory standard) |
| Traceable drugs administered outside prescription chart | Yes — lidocaine administration documented outside any prescribing chart | No — no comparable documented-drug-outside-chart evidence |
| Psychiatric diagnosis | Yes — factitious disorder by proxy (Munchausen’s by proxy) diagnosed by defence-instructed psychiatrists | No — no psychiatric or psychological diagnosis of factitious or related condition |
| CCTV / swipe-card trace | Not a feature of the 1993 evidential record (pre-CCTV era) | Contested — swipe-card and CCTV data presented at trial has been disputed post-conviction (see CCTV/swipe-card evidence) |
| Shift-pattern statistical analysis | Secondary — used after direct evidence was established | Primary — the shift-rota chart was foundational to the Crown’s case (see shift statistics) |
| Forensic pathology standard met | Yes, by the standards of the early 1990s | Contested — independent re-readings as part of the October 2025 CCRC application (see forensic-pathology standard) |
| Panel of independent international experts post-conviction | Not applicable (case not under active review) | Shoo Lee International Expert Panel (February 2025): finding of no medical evidence of deliberate harm in any reviewed case |
What the comparison shows
On the Clothier Inquiry record, the Allitt conviction rested on direct evidence — eyewitness, physical traces, stolen unit property, documented drug administration outside prescribing charts, anomalous electrolyte readings at forensic-grade laboratories, and a psychiatric diagnosis. The shift-pattern analysis was secondary, applied to an evidential core already established by direct evidence.
The Letby trial record has a different architecture. The shift-rota chart was foundational rather than secondary; there was no direct eyewitness to any alleged act; no contemporaneous physical-evidence chain; no anomalous electrolyte profile matching the Clothier standard; no confirmatory mass-spectrometry on the insulin screening immunoassay; no psychiatric diagnosis of factitious or related disorder.
The question the comparison raises is not whether Ms Letby is innocent or guilty. The question it raises is whether the ‘another Allitt’ analogy that the investigation adopted from 2017 onwards survives comparison with the Clothier evidential standard. The comparison above is the factual basis on which readers can weigh that question themselves.
Why this framing matters for the CCRC review
The CCRC review threshold under section 13 of the Criminal Appeal Act 1995 is the real-possibility test: is there a real possibility the Court of Appeal would overturn the conviction on new evidence that was not before it at direct appeal? The Shoo Lee Panel report, the Joint Insulin Report, the paediatric-pathology re-readings, the Fenton Bayesian analysis, the Heneghan/Goldacre EBM critique, and the January 2026 CPS decision not to extend the pattern on further candidate cases are all post-2024-appeal evidential developments. The Clothier-standard comparison is one of several frames the CCRC reviewers can apply.
Read alongside
- Analysis: the Allitt framing effect
- Evidence: the ‘gang of four’ framing
- Analysis: the post-conviction evidence arc
- Evidence: core insulin issue
- Evidence: Guildford forensic-laboratory standard
- State of the evidence (April 2026 rollup)
Source
Clothier Inquiry Report (1994) on the care of paediatric patients at Grantham & Kesteven General Hospital; Shoo Lee International Expert Panel Report (February 2025); Joint Expert Witness Insulin Report on Babies F and L (May 2025); trial transcripts (R v Letby 2022-2023, R v Letby retrial 2024); forensic-pathology literature and the Royal College of Pathologists neonatal-autopsy guidance.
Last verified: 22 April 2026.