Lawyers for Lucy Letby, a nurse convicted of murdering seven babies, are seeking a review of her convictions after an expert witness altered his stance on the causes of death for three infants. Mark McDonald, Letby’s barrister, claims that Dr. Dewi Evans, the prosecution’s lead expert, has revised his opinion, which may have impacted previous court rulings. Letby, serving 15 life sentences, is challenging the reliability of expert testimony and aims to appeal this unprecedented legal scenario.