Letby, who was a neonatal nurse at the hospital, was convicted in August of murdering seven babies and attempting to kill six more, making her the worst child serial killer in modern British history. Last month she formally lodged an attempt to challenge her convictions at the court of appeal. After her conviction, ministers swiftly announced an inquiry into the lessons that could be learned from her crimes and the length of time it took to discover who was responsible for the deaths. After pressure from bereaved families and others, the inquiry, to be led by the senior judge Dame Kate Thirlwall, was put on a statutory footing, meaning it has the legal powers to compel witnesses to give evidence. The first area covered by the inquiry will be the experiences of all the parents of babies named in the indictment for Letby, at the Countess of Chester hospital and with other relevant NHS services. The second element will examine the conduct of hospital staff and managers, including whether suspicions should have been raised earlier, whether Letby should have been suspended earlier, and whether suspicions about her could have been passed to police sooner. This will include examination of the culture at the hospital and the role of its senior management and board. The final strand will cover “a consideration of NHS culture” and the wider effectiveness of “NHS management and governance structures and processes, external scrutiny and professional regulation in keeping babies in hospital safe and well looked after, whether changes are necessary and, if so, what they should be,” the department said. Steve Barclay, the health secretary, said: “Losing a child is the greatest sorrow any parent can experience and I cannot begin to imagine the hurt and suffering experienced by the families affected by Lucy Letby’s horrific crimes. “We have a duty to get them the answers they deserve, to hold people to account where they need to be, and to make sure lessons are learned. These terms of reference have been agreed following engagement with the families and I am confident Lady Justice Thirlwall will ensure their voices are heard as the inquiry gets under way.”