Context
The Crown’s closing speech at the original Letby trial was delivered by Nicholas Johnson KC, who led the prosecution, over four days from Monday 19 to Thursday 22 June 2023. It was the Crown’s final synthesis of the evidence to the jury before the judicial summing-up. This page tracks the speech’s principal themes and, for each, the post-conviction independent-expert response.
Correction, 5 September 2026. This page previously said that Kate Blackwell KC, Senior Treasury Counsel, led the prosecution and gave this speech. That was wrong. The prosecution was led by Nicholas Johnson KC. Kate Blackwell KC appears in this case as counsel at the Thirlwall Inquiry, where she acts, in her own words to the Inquiry, “on behalf of the former senior managers”. She had no part in the Crown’s closing. The URL is left as it was so that existing links do not break.
The air-embolism strand
The Crown’s closing framed the air-embolism mechanism as established across multiple indicted cases on the authority of Dr Shoo Lee’s 1989 paper. The jury was invited to read the skin-sign evidence as diagnostic. Post-conviction, Dr Lee himself has publicly stated the skin signs at trial do not meet his paper’s criteria. The fourteen-strong Panel has confirmed this case-by-case.
The insulin strand
The closing framed the Baby F insulin result as forensic proof: “you cannot argue with a lab result”. Post-conviction, the Joint Expert Witness Insulin Report on Babies F and L concludes you can and must argue with this particular lab result — a screening immunoassay without confirmatory mass spectrometry, processed under clinical not forensic chain of custody. See our Baby F deep-dive.
The shift-rota strand
The closing presented the shift chart as a pattern so improbable it could only be explained by deliberate harm. Post-conviction, Prof. Richard Gill and Prof. Peter Green have identified the selection-effect problem: the 25 events were selected partly on Letby’s presence; her shift attendance against that selection generates the visual match by construction. See our base-rate analysis.
The notes strand
The closing asked the jury to read “I am evil I did this” as a confession. Post-conviction, the clinical-psychology expert reports filed with the CCRC application identify the notes as the recognisable signature of private self-blame writing by a clinician under sustained institutional accusation. See our self-blame psychology analysis.
The digital-evidence strand
The closing framed the Facebook searches and search-history as evidence of fixation. Post-conviction, independent nursing commentary has placed these behaviours against the denominator of typical UK NICU nursing practice. The selected subset was not shown with its denominator. See our Facebook-searches analysis and preparation-evidence analysis.
The institutional-context strand
The closing framed the consultants’ 2016 concerns as independent corroboration of the medical evidence. Post-conviction, the Thirlwall Inquiry evidence has documented the institutional failure chain: the RCPCH review as decoy, the apology-letter sequence, the eight-month delay to police, the executives subsequently arrested on suspicion of gross negligence manslaughter. See our doctor-nurse power dynamics analysis.
Read alongside
Defence closing speech summary, Myers KC closing expanded, Judge’s summing-up, Evidence: circular evidence.