Two leading experts have withdrawn from the defense team of Lucy Letby, a former neonatal nurse convicted of murdering seven babies and attempting to murder seven others at the Countess of Chester hospital in northwest England. The experts, Helen Shannon and Geoff Chase, cited concerns over the "scientific credibility" of some of the evidence being used in her defense. The Criminal Cases Review Commission (CCRC), a UK body that investigates potential miscarriages of justice, is currently reviewing a dossier of evidence submitted on Letby’s behalf last year. However, Shannon and Chase have now stepped back from supporting certain arguments in the case. Letby, who was convicted in 2023, is serving 15 life sentences for the alleged crimes, which took place between June 2015 and June 2016. A key part of the prosecution case involved the claim that she poisoned two newborn boys, Baby 6 and Baby 12, by adding insulin to their feeding bags. Shannon and Chase had previously submitted a 100-page report questioning the scientific basis of these convictions, stating there was a “very strong level of reasonable doubt.” They maintained that it was “very unlikely” anyone had poisoned the infants. However, they have now stated that they cannot support other aspects of the defense team’s arguments related to the insulin cases. In a letter to the CCRC, the experts warned that some of the arguments being advanced by Letby’s defense team were inconsistent with the available scientific evidence and established medical physiology. They expressed concern that the defense strategy, led by barrister Mark McDonald, was placing Letby’s long-term interests at risk and could also harm the families of the victims. The experts said they could not ethically support arguments they believed were inaccurate, as doing so would violate professional codes in both the UK and New Zealand. McDonald responded by stating that new evidence from international experts in insulin and endocrinology undermines the scientific foundation of the original trial. He emphasized that the case is not dependent on a single expert but on a convergence of findings across different disciplines. The CCRC has been reviewing Letby’s convictions for 18 months but has not commented on the recent developments. Meanwhile, a public inquiry led by Lady Justice Kathryn Thirlwall is set to release its findings on Tuesday. The inquiry is expected to examine missed opportunities by hospital management to act on concerns raised by doctors about unexplained deaths on the neonatal unit in 2015 and 2016. A separate criminal investigation is ongoing into potential corporate manslaughter and gross negligence at the Countess of Chester hospital.