Why her role matters
Senior Treasury Counsel are the senior barristers instructed by the Crown in the most serious criminal cases. Their deployment reflects the Crown Prosecution Service’s own assessment of the gravity of the case. Ms Blackwell KC’s leadership of the prosecution is therefore itself a marker of how the Crown viewed the case.
Her closing speech to the jury is the Crown’s synthesis of its case at the moment the jury was about to retire. The specific framing she advanced — six mutually-corroborating strands of evidence — is the framing independent review has subsequently identified as circular rather than independently convergent.
Professional background
- Senior Treasury Counsel. Senior Treasury Counsel are a small group of senior barristers instructed by the Crown in the most serious cases.
- King’s Counsel (KC). Previous extensive criminal practice on the Northern Circuit.
- Led the Crown at the original Letby trial (Manchester Crown Court, October 2022 – August 2023).
- Led the Crown at the Child K retrial (Manchester Crown Court, June–July 2024).
The six-strand closing framing
The Crown’s closing speech presented its case as built on six mutually-corroborating strands:
- The air-embolism mechanism supported by Dr Dewi Evans’s causation opinion.
- The Roche Cobas insulin immunoassay result on Babies F and L.
- The shift-rota chart on the 25 selected events.
- The handwritten Post-it notes.
- The Facebook searches and search history.
- The handover sheets retained at home.
Independent review since 2024 has identified that the strands are not independent of each other. Each strand rests on the premise that the cluster requires a criminal explanation — and the cumulative argument only works if the strands are treated as mutually corroborating. When each is examined individually, the evidential weight is much less than the Crown’s closing suggested. See our circular evidence analysis.
Why this biography is on the site
Public-record transparency. The prosecutor who led the case is a material figure in the trial record. Providing a neutral biographical entry is a matter of public-record completeness, not personal criticism. The framing Ms Blackwell KC advanced at trial is the framing the CCRC review now considers.
Role at trial
Kate Blackwell KC was junior prosecution counsel at the 2022-2023 Letby trial and led the Crown’s closing submissions on a number of counts. Her closing arguments are part of the public-record trial transcripts. She worked alongside Nicholas Johnson KC as lead prosecution counsel and Simon Medland KC as a fellow junior.
Ms Blackwell’s closing speech contributions addressed the circumstantial-evidence framework for the case: the shift-rota chart, the handover-sheet retention, the Facebook-search pattern, and the handwritten notes. Her presentation of these elements as a coherent circumstantial pattern is one of the rhetorical structures the post-conviction critique now engages.
The two-junior prosecution team structure
The Crown’s prosecution team at the Letby trial included Nicholas Johnson KC as lead and two junior silks (Medland KC and Blackwell KC). The three-counsel structure is standard for complex multi-count Crown prosecutions. The junior silks carried significant portions of the witness-examination workload and contributed to the closing-submissions structure. Ms Blackwell’s share of the closing speech is documented in the Chester Standard live-blog records of the trial.
Why this biography is on the site
This biography is a reference page, not a commentary on Ms Blackwell personally. Her role at trial is part of the public record and identifying her here allows readers to navigate the trial transcripts, the Chester Standard live-blog records, and the post-conviction analysis of the Crown’s presentation. The conviction-safety question is about the evidential architecture of the case, not about the conduct of individual counsel; this page provides the factual identification that allows readers to navigate the public record.