How a 25-year-old nurse became one of the UK's worst serial killers.

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"I have always wanted to work with children."

It's a phrase you might expect from a nurse who chose to spend their working days caring for babies and children. But these simple words took a sinister turn when spoken by Lucy Letby, as she stood trial for the murder of seven babies, and the attempted murder of six others.

At the time of her arrest, Letby was a neonatal Nurse, a profession, according to clinical and forensic psychologist Dr Ahona Guha, "where people are deified and implicitly trusted".

This was certainly the case for Letby, who was entrusted to care for the most vulnerable babies at the Countess of Chester Hospital's infant intensive care unit.

Instead, she did the unthinkable, abusing her position of unquestioned power to take away their tiny lives before they'd even begun.

Dr Guha told Mamamia Letby's attraction to working with babies and what they symbolised to her was "an interesting question" — one many people are still trying to make sense of.

"It's so unusual to see babies as victims," she said.

"What is really fascinating about Letby is how studiously normal she looked," Dr Guha added.

"She didn't have the usual risk factors we expect — no poverty, abuse, trauma, deprivation, parental substance addiction, or justice involvement."

Listen to True Crime Conversations unpack the trial of Lucy Letby. Post continues below.

From aspiring graduate to the UK's most prolific child serial killer.

Letby was the first person in her family to attend university, studying nursing at the University of Chester. Almost all of her work placements were at the Countess of Chester Hospital, either on the children's ward or the neonatal unit.

In January 2012, Letby began working full-time at the hospital, before qualifying to work with the intensive care babies in 2015.

The court was told by Letby herself that she spent most of her time looking after the "sickest babies" on the unit. She estimated she cared for hundreds of newborns during 2015 and 2016.

When an alarming spike in infant deaths and unexplained collapses occurred in the hospital's neonatal unit, an investigation was launched. It led police to Letby's front door.

Throughout the investigation, police interviewed doctors, nurses and hospital administrators, while combing through hospital records. One such document showed Letby was on shift every time one of the babies collapsed or died.

In July 2018, aged just 28, Letby was arrested in her home, led away in handcuffs. She was released on bail, and following two more arrests, was charged in November 2020.

Letby denied all 22 charges against her, which included the murder of seven babies and the attempted murder of 10 others.

Watch: The actual footage of Lucy Letby arrested in her home. Post continues after video.

What was revealed during the Lucy Letby trial?

Letby continues to steadfastly deny any wrongdoing, despite police finding a post-it note in her bedroom, scrawled with the words: I AM EVIL. I DID THIS!

Letby's defence barrister denied the note was an admission of guilt, but rather "the anguished outpouring of a young woman in fear and despair".

However, the prosecution told a different story — one of a cold-blooded killer trying to 'play God' and hide it by falsifying medical records, gaslighting colleagues, and connecting with grieving parents.

The court was told Letby once sent a condolence card to the parents of a baby she was accused of trying to kill three times, finally succeeding the fourth time. She spent time with another set of parents, photographing their deceased children.

Policing Academic Associate Professor Dr Michael Kennedy drew comparisons to the Kathleen Folbigg case, where diary entries were used to convict Ms Folbigg of the murder of her four children.

"Experts advised that 'coincidence' was unlikely. This also occurred in the Letby matter."

DNA later proved the possibility of natural causal factors in the children's death, and Folbigg was subsequently released.

During the nine-month-long trial, jurors were shown pictures of her home, prompting tears from the accused. The photos showed a child-like bedroom, adorned with fairy lights, stuffed toys, and affirmation posters.

After 110 hours of deliberation, the jury convicted her of seven counts of murder and six counts of attempted murder and in August 2023, she was sentenced to 14 whole-life terms — meaning she will never walk free.

Almost a year later, in July 2024, Letby was convicted of attempting to murder another newborn and sentenced to a 15th whole-life term.

Letby once again denied any involvement in the baby's death, telling the judge, "I'm innocent".

She has since lost two appeals — one in May 2024 for the original seven murders and seven attempted murders, and another in October 2024 for the attempted murder of a baby girl.

In February 2025, Letby launched a 'last resort' application to the Criminal Cases Review Commission, a statutory body that investigates cases where people believe they've been wrongly convicted or sentenced and can send cases back to the Court of Appeal.

A review process by the CCRC could take at least a year.

Police said they were reviewing the case of 4,000 admissions of babies into neonatal units at hospitals where Letby worked or trained.

In January 2026, the Crown Prosecution Service (CPS) declared Letby would face no new criminal charges over baby deaths and collapses at hospitals where she worked.

The CPS said it had reviewed evidence into further allegations of murder and attempted murder against nine children at the Countess of Chester Hospital and Liverpool Women's Hospital, but "the evidential test was not met in any of those cases".

Meanwhile, a public inquiry, headed by Lady Justice Thirlwall, into how Letby was able to commit her crimes is currently ongoing, with the final report expected to be released "after Easter 2026".

Why did she do it?

Determining a motive for such a heinous crime has proven difficult, particularly as Letby has continued to plead innocence.

Detective Superintendent Paul Hughes of Cheshire Police said Letby clearly "loved the attention".

"But if we are looking for why she's done this, then to re-use her own words, 'she is evil, and she did this'."

Dr Guha said it's most likely more complex than this.

"It's really unusual to have a female serial killer, and the small number that do exist often offend with partners or for financial motives. All we are left with then, is her personality formation. This is the crux on which everything hinges and where motives might be found in the absence of any other obvious motives, like money or passion."

Assoc Prof Kennedy agreed that while there are many possible explanations for the murders, the least likely is that Letby is evil.

"Mental Health plays a huge role in these matters. It is not to say that the accused people do not understand their actions are wrong or they should not be incarcerated," he explains.

"For me, the behaviour of Letby is best explained by Munchausen's syndrome. It's a cry for attention and help and a need to be valued and useful."

Dr Guha suggested Letby could have narcissistic or psychopathic traits.

"She appears to present as much younger and more unformed than she should be – based on chronological age," Dr Guha of Letby, who is now 36.

"What does this mean in terms of her capacity to connect, find attention and care, and make her way in the world as an adult would?

"From a personality structure, it's probably likely she had at least some narcissistic or psychopathic traits. It would be hard to kill infants and watch distress if you didn't have the capacity to not feel emotion."

How did she get away with it for so long?

As well as Letby's clever manipulation of her trusted role and relationships with colleagues, both Dr Guha and Assoc Prof Kennedy believe system failure played an integral role in her ability to continue to murder babies without ramification.

The court heard several doctors had reported concerns about Letby to hospital management as early as 2015. "This takes toxic workplace to a whole new level, and really points to the harm which can arise when concerns are not acted upon appropriately," Dr Guha says.

"It's unlikely that this would have been noticed at the outset. But it sounds like once it was noticed, there was protection for her by hospital management."

Assoc Prof Kennedy described the events as a "fascinating case of workplace dynamics".

"It seems 'red flags' appeared ages ago, but she knew how to navigate her way through," he said.

"The other factor is senior management engaging in brand name protection for their institution, their executive colleagues, and of course themselves. This factor is very evident in the Letby matter, where, despite years of concern regarding her behaviour, they failed to notify authorities.

"In the end this failure has likely resulted in deaths that could have been avoided."

Is rehabilitation possible?

"I for one wouldn't want to be letting Letby around anyone with any medical or physical or psychological vulnerabilities," Dr Guha said.

"And a specific note on mental health... it doesn't cause offending of this nature – unless for instance, she was psychotic before each murder.

"Many people have mental health difficulties and the majority of them don't go to kill babies. In the forensic world, we look for a causal link, not just a correlation."

Assoc Prof Kennedy noted rehabilitation is possible, but doesn't always work.

"Sadly, there are also some who need to remain in jail."

This article was first published in 2023 and has been updated with new information.

If you find yourself needing to talk to someone after reading this story, please call Lifeline on 13 11 14.

Feature Image: Facebook/Reuters: Cheshire Constabulary/Handout.