Netflix's Lucy Letby documentary: 7 details that may leave viewers questioning the nurse's guilt

A new Netflix documentary, The Investigation of Lucy Letby, puts forward the divisive case of a children's nurse who was found guilty of seven counts of murder and six counts of attempted murder.

It features interviews with those who believe Letby was both rightly and wrongly convicted – with latter side arguing she was used as a scapegoat by the NHS hospital she worked for, the Countess of Chester, which was failing to meet care standards.

The hospital declined to comment on The Investigation of Lucy Letby citing a separate n ongoing inquiry into gross negligence and corporate manslaughter.

For Letby's parents, the documentary is an "invasion of privacy" as it features intimate footage of their daughter's arrest inside their family home – something the film's producer and director defended during an exclusive interview with Cosmopolitan UK.

Here are seven key details in the ITN production which invite readers to question whether or not Letby is an example of the justice system getting it right or wrong.

The documentary looks at a key piece of evidence in the case; a handwritten note from Letby that appears to be a confession.

A sheet of paper featuring the words ‘I killed them on purpose because I am not good enough’ is shown alongside footage of Letby initially telling police officers during an interview, “I wrote it because everything had got on top of me” and that she did so after being moved off the intensive care unit she worked on while under investigation – and being encouraged, by a counsellor, to write her thoughts and feelings down to process her situation.

“I felt like they were blaming my practice, that I’d hurt [babies] without knowing,” Letby said. “That made me feel guilty.”

The same note also says ‘fear’, ‘panic’ and ‘I haven’t done anything wrong’.

Letby's friend, Maisie*, a nurse who also worked at the Countess of Chester for a time, argues that the defence didn’t put forward anyone to give an alternative explanation or opinion as to why Letby wrote this seeming confession.

Letby’s defence barrister, Ben Myers KC, declined to comment on why his team did not call on any expert witnesses during the trial.

In the documentary, police say Letby was the only person present during the collapse of 25 babies and the deaths of 17, and that once Letby was suspended, the incidents stopped.

However, the unit Letby worked on was also downgraded after she left, meaning it did not receive as many seriously unwell babies which could have also impacted the mortality rate.

Between June 2015 and 2016, it is reported that there were 13 unexpected deaths on the neonatal ward where Letby worked. When examining the cases, independent paediatrician Dr Dewi Evans said, the related medical files indicated someone had “intentionally harmed these babies” – which led police to change tact and instead stop asking ‘What happened?’ but ‘Who did it?’.

However, a lot of the evidence in Letby's case was dense and medically complicated, which criminal barrister Mark McDonald is now trying to argue could have made it difficult for jurors to follow and which leaves room for misinterpretation.

Dr Dewi Evans seen in Netflix’s The Investigation of Lucy Letby

In court, two of the babies' cases were presented as being clear cut: insulin was administered when it was not needed, which can cause coma or death, something the prosecution argued Letby would have known.

Letby’s team agreed insulin had been administered without need, which the nurse accepted, but she did not accept it was her who was responsible. However, Letby's signature was on the nutrition bags that the prosecution alleged were contaminated with insulin.

The defence team argued there is no evidence Letby was the one to tamper with the bags.

The prosecution put forward a rota showing Letby was on shift whenever a baby fell critically ill or died, painting a clear picture that she was on the scene. McDonald is seen arguing that of course she was present: she was a highly-skilled nurse who had done extra training courses, and who regularly took on extra shifts.

McDonald points out Letby was never seen doing anything nefarious on CCTV and argues that she did not have a clear motive.

For the first time, a parent who lost a child under Letby's care speaks in a documentary: Sarah* appears anonymised and talks of the heartbreak that followed the death of her daughter, Zoe*.

In The Investigation of Lucy Letby, Sarah says, “They [the hospital] failed me, they failed Zoe, but every doctor, nurse and expert all clearly said Zoe was improving. She was getting better [before her sudden death].”

Sarah also describes coming face to face with Letby in court, saying she went into the trial with an unbiased approach. “She looked at me a dozen times, staring. Every time, I’d have to look down,” the bereaved mother recalled, detailing how Letby claimed not to remember Zoe, but said she remembered all the other babies she was accused of murdering or attempting to murder.

Dr Evans states in the documentary that baby Zoe appeared to be stable and there was no obvious reason why she collapsed. He adds that medical staff reported a rash on Zoe that they’d never seen before and which he believes was the result of air being injected into a blood vessel, stopping circulation.

Hundreds of confidential handover sheets were found in Letby’s home during a police search*. When questioned on it, the nurse claimed she had accidentally taken all of the sensitive paperwork containing private medical information home in her pocket.

When asked why she didn’t shred them after realising her error, Letby said she didn’t have a shredder – however, police found one in her home.

Officers also found diary entries from Letby containing initials relating to babies who were unwell or who died on the relevant dates.

McDonald organised a panel of medical experts, including Dr Shoo Lee, whose work Dr Evans used to help inform his decisions on why the babies died or rapidly deteriorated.

Dr Lee said his panel’s report concluded there had been misdiagnoses, inadequately trained personnel on hand, and that it was hard to find a doctor when the need arose. A consultant from the hospital Letby worked in juxtaposes this, saying they’d had staffing issues in previous years without the high death rates they faced during Letby's tenure.

Dr Evans argues that Dr Lee did not produce any new evidence, just new opinions.

* This article was changed on 2 April 2026 from an original report that 250 documents were found in a box entitled 'keep', when in fact 257 documents were found in various places across Letby's home.