Who is Dr Dewi Evans?
Dr Dewi Evans was the Crown’s lead causation expert across most counts. He is a retired paediatrician, formerly of Singleton Hospital, Swansea. He had not worked in routine neonatal intensive care for over a decade at the time of the 2022–2023 trial. He reportedly approached Cheshire Police offering his services on the case before being formally instructed.
The diagnostic framework he applied
For several counts, Dr Evans told the jury that the skin discolouration patterns described on post-mortem and contemporaneous photographs were characteristic of air embolism, and he cited the Lee & Tanswell 1989 paper as authority. For the insulin counts, he endorsed the Royal Liverpool laboratory immunoassay as diagnostic of exogenous insulin. For the Child K count at retrial, he supported the interpretation that a dislodged ET tube plus Ms Letby’s presence constituted attempted harm.
What independent experts now say
Dr Shoo Lee himself — the co-author of the 1989 paper Dr Evans relied on — has stated publicly that the skin signs described at trial do not match those in his paper. The Panel rejects Dr Evans’s air-embolism methodology across all indicted counts. On the insulin evidence, the Panel and independent endocrinologists emphasise that the Roche immunoassay was a screening test never validated for forensic use. On Child K, the Panel concludes ET-tube dislodgement is routine at 25-week gestation and not evidence of wrongdoing.
A separate family-court judge in 2023 described an unrelated Evans expert report as “worthless” for its methodology.
Full archive
The near-verbatim archive of Dr Evans’s trial testimony is maintained by lucyletbyinnocence.com. We link through to it for the unabridged text.
Read alongside
Dr Evans methodology issue, air-embolism evidence, insulin evidence, the Panel press conference.