Lady Justice Thirlwall's public inquiry into events at the Countess of Chester Hospital between June 2015 and June 2016 has found a "dysfunctional" management culture and an "us-versus-them" mentality that allowed nurse Lucy Letby to continue murdering and harming babies. The report concluded there was a "complete failure at all levels" to invoke safeguarding procedures, with staff who raised concerns being dismissed and internal reviews conducted in place of contacting police, delays that could otherwise have prevented deaths and injuries.

The inquiry, which did not examine Letby's guilt itself, revealed mixed feedback on her performance during training, including concerns about her communication skills and drug calculations, and found she had been "repeatedly untruthful" with colleagues while remaining close to senior managers. The judge singled out executives Alison Kelly, Ian Harvey and Tony Chambers for dismissing suspicions about Letby as late as June 2016, and described as "reprehensible" the treatment of victims' parents, four of whose mothers were found to have been misled about investigations into their children's deaths.