Two experts who previously supported efforts to challenge Lucy Letby’s convictions have withdrawn from her defence team, citing concerns over the scientific credibility of some of the evidence presented. Helen Shannon, a British chemical engineer, and Geoff Chase, a New Zealand-based bioengineering professor, said they no longer endorse certain aspects of the defence strategy, which they believe contain "unresolvable problems" conflicting with established science.
Letby, 36, is serving 15 whole-life sentences after being convicted at Manchester Crown Court for the murder of seven babies and attempted murder of seven others at the Countess of Chester Hospital. She maintains her innocence and is actively challenging the verdicts. The Criminal Cases Review Commission (CCRC), the body responsible for examining potential miscarriages of justice, has been reviewing evidence submitted by a panel of experts last year, which included Shannon and Chase, alongside Canadian neonatologist Dr. Shoo Lee.
The expert panel produced a detailed report arguing that no murders had occurred and suggesting that the babies’ deaths were attributable to natural causes or inadequate care. In a public statement earlier this year, Dr. Lee asserted that the deaths were not linked to poisoning. However, Shannon and Chase have since expressed reservations about some of the defence’s medical arguments, particularly those concerning insulin-related cases from the trial. They maintain their position that it is "very unlikely" that specific infants, known during the trial as Babies F and L, were poisoned with insulin but cannot support other defence claims that they believe contradict existing medical knowledge and physiology.
In correspondence with the CCRC, Shannon and Chase cautioned that while it is acceptable for the defence to present multiple lines of argument, some currently advanced by Letby’s legal team lack scientific grounding and are problematic. Their withdrawal has raised questions about the robustness of the defence’s case.
The expert panel’s impartiality came under scrutiny earlier this year after it was revealed that Dr. Lee had sent a message to medical staff involved in the case expressing that the panel "might be her (Letby’s) last hope," which some critics argued suggested bias. One senior neonatologist declined to participate in the panel, citing concerns about the tone of Dr. Lee’s communications.
Separately, Mark McDonald, Letby’s barrister, has faced a professional misconduct complaint filed with the Bar Standards Board, reportedly by families of the victims. McDonald responded to the experts’ withdrawal by emphasizing that Letby’s defence does not depend on a single expert witness.
The CCRC, which has been reviewing Letby’s case for about 18 months, has not issued a comment. A public inquiry into the deaths associated with Letby is scheduled to release its findings shortly.