Police have been investigating the senior leadership team at the Countess of Chester Hospital following Lucy Letby’s murder and attempted murder convictions.

Three people who were part of the senior leadership team at the hospital where convicted baby killer nurse Lucy Letby worked have been arrested on suspicion of gross negligence manslaughter.

Cheshire Constabulary said the suspects, who occupied senior positions at the Countess of Chester Hospital (CoCH) between 2015 and 2016, were arrested on Monday.

Following the lengthy trial and conviction of Letby in August 2023, the police force launched an investigation into corporate manslaughter, and later gross negligence manslaughter, at the hospital – leading to the latest arrests.

Police have said investigations at the Countess of Chester are continuing and that the probe does not impact Letby’s multiple murder and attempted murder convictions.

Here’s what we know so far.

What we know

The three suspects, who occupied senior positions at the CoCH between 2015 and 2016, were arrested on Monday on suspicion of gross negligence manslaughter.

All three have since been bailed pending further inquiries, the force added. Police said corporate manslaughter and gross negligence manslaughter probes are continuing.

Cheshire Constabulary said it launched its investigation into senior management at the hospital in October 2023, a few months after Letby’s conviction.

Its corporate manslaughter probe is focusing on “senior leadership and their decision-making to determine whether any criminality has taken place concerning the response to the increased levels of fatalities”, Detective Superintendent Paul Hughes said.

In March 2025 the scope of the investigation widened to also include gross negligence manslaughter – a separate offence which “focuses on the grossly negligent action or inaction of individuals”, police added.

Nurse Lucy Letby was found guilty of murdering seven babies and attempting to kill a further six more in August 2023, and later sentenced to another whole life order in July 2024. (Alamy)

What we don’t know

Police are yet to reveal the identities of the three people who were arrested, as it is standard for authorities to only name suspects publicly once they have been formally charged.

While we know that the three suspects were part of the hospital’s senior leadership team, it is not clear exactly what jobs they held, or what their working relationship was with Lucy Letby.

The investigation followed Letby’s convictions, but it is not known whether the alleged cases of gross negligence are directly linked to the 35-year-old former nurse’s actions at the CoCH.

A spokeswoman for CoCH reiterated it “would not be appropriate” for the hospital to comment “due to the Thirlwall Inquiry and the ongoing police investigations”.

What is gross negligence manslaughter?

According to the Crown Prosecution Service (CPS), gross negligence manslaughter is committed where the death is a result of a grossly negligent (though otherwise lawful) act or omission on the part of the defendant.

Circumstances where this can occur are “almost infinitely variable”, the CPS says, but here are some examples that could apply:

Death following medical treatment or care; the offence can be committed by any healthcare professional, including but not exclusively doctors, nurses, pharmacists, and ambulance personnel.

Deaths in the workplace the offence can be committed by anyone who is connected in some way to a workplace of any nature. The context is wide ranging but can include offices, factories, ships, airports, aeroplanes, construction sites, oil rigs, farms, schools and sporting grounds. The deceased victims may be employees, contractors, sub-contractors, and members of the public visiting or passing by the workplace when a fatal incident happens.

Death in custody – a death in custody is a generic term referring to deaths of those in the custody of the state. In this context the offence can be committed by police or prison officers, dedicated detention and other custody assistants, and by healthcare professionals who are responsible for the care of those detained in a custodial setting.

According to the Sentencing Council, gross negligence manslaughter is triable only on indictment, and carries a sentencing range of 1 – 18 years in custody.

The length of sentence for this offence is determined by a scale of culpability (category A being the highest and D being the lowest), as shown on the council’s website.

Repeated negligence, blatant disregard for high risk of death and motivation by financial gain are all considered for higher penalties.