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The Welsh doctor whose evidence convicted baby killer Lucy Letby

21 Aug 2023 9 minute read
Dr Dewi Evans. Photo Peter Byrne/PA Wire

Martin Shipton

The Welsh doctor who established that the babies murdered by nurse Lucy Letby were victims of crime has spoken in detail about how he arrived at his conclusion.

Dewi Evans, a retired consultant paediatrician from Carmarthen, was one of two clinical experts who provided detailed medical evidence to Cheshire Police that resulted in Letby’s conviction at Manchester Crown Court for seven murders and six attempted murders at the Countess of Chester Hospital..

In an interview with TalkTV, Dr Evans said he felt justice had been done: “I think this is horrific. It’s probably the single most appalling event in any NHS hospital over the last 75 years. It is beyond belief what happened to these babies and it is beyond belief why she got away with it for such a long time.

“Everyone who had a duty of care to these babies failed the babies and failed their families. I think my profession was a bit on the slow side to pick these things up, but the responsibility most of all rests with NHS managers at Chester who failed to listen to the consultants despite their concerns three months after the first event.”


Asked why the profession had been slow to pick up what was going on, Dr Evans said: “The last thing you expect of your staff is that they will be harming babies, harming their patients. So that was the main problem.

“The other problem is that managers have taken over far too much control over the care of patients, and as a result of that doctors are loath to raise concerns because they are used to being ignored or dismissed or even being told, as in this case, to apologise to the perpetrator of these horrendous crimes, which is what happened prior to Cheshire Police and myself becoming involved in 2017.”

Undated handout photo issued by Cheshire Constabulary of Lucy Letby.

Explaining how he had become involved in the Letby case, Dr Evans said: “I’ve been involved with medical legal work for over 30 years and I’ve dealt with a number of cases alleging clinical negligence, not deliberate harm, involving babies.

“Since 2013 I’ve been involved with a couple of dozen cases for police authorities via the National Crime Agency, so my name was well known to them, and I thought this was a case that I was suited to. I had the clinical experience, because I had been involved with the care of babies from my mid-20s, throughout my professional career, and in addition I was familiar with the medical legal system, so this was my kind of case.”


He said he had got involved in the case in May 2017, and told Cheshire Police not to tell him if they suspected anyone of being responsible for criminality: “In other words, I wanted to investigate the cause of the deaths of these babies. I was not there to investigate the crime. At that time I was unaware of the name Lucy Letby or anyone else.

“I received a copy of the clinical notes of over 30 babies who had either died or collapsed between January 2015 and July 2016, and I looked at all of them. Some of these cases you could understand why the babies had died.

“They died of problems with small babies – haemorrhage, infection, a congenital problem, for instance. But I identified 15 babies whose collapse I could nor explain as a natural cause. In addition to that, their collapse was not only unexpected but I felt was due to a condition we call air embolism. It was as if someone had injected air into their circulation directly.

“Other babies collapsed in my opinion as a result of someone injecting loads and loads of milk, or milk and air, directly to the stomach. If you inject loads and loads of milk into the stomach of a small baby, it will interfere with their breathing, because the diaphragm can’t go up and down and therefore they collapse.

“Other babies suffered direct trauma. They were found with blood around their mouths or blood at the back of the throat.

“So all of these baby collapses could not be explained at all, other than someone had caused harm to them. And then later, in 2018, I found two more cases. These were the second of two separate lots of twins who had low blood glucose levels.

“Low blood glucose or low blood sugar is common in small babies, but a very astute medical officer in Chester had measured these babies’ insulin level, and the insulin level was very, very high, which could not be explained on the basis of their producing their own insulin.

“So in addition to the other instances of trauma, we now had two babies who had had insulin injected into their systems. This was an additional concern and not something that anyone had suspected initially. In fact, I owe it to Cheshire Police for being obsessive and methodical in the investigation.

“I only saw the insulin poisoning because they were the second set of twins who had been harmed in other ways. So this was a complete shock to me and a complete surprise – but it was quite important, because at last one could find some kind of smoking gun. In other words, one could now show that someone was causing harm to babies, whereas with the injection of air, unless someone sees you doing it, it would have been difficult to prove that these babies were placed in harm’s way.”

Duty roster

Dr Evans said he had sent the reports to Cheshire Police and told them they needed to look at the duty rosters for each of the events, to see which nurses and which doctors had been on duty at the times when the babies were harmed.

He said: “If you have a small baby, that baby will deteriorate very quickly, within seconds or minutes. It soon became apparent, even after the first four babies, that there was only one nurse who was on duty for all of the events, and that was Lucy Letby. Later it emerged that she was on duty for all 17 occasions when one or other of these babies collapsed or died.”

Asked whether the methods Letby had used to harm the babies made it difficult to detect what had happened, Dr Evans said: “She was an extremely clever criminal. She almost got away with it. They may well deny it, yet but for the consultants pressing and demanding that the police got involved, I think she could well have got away with this.

“I’m sorry to say this, but it’s no surprise to me, although it’s shocking to everyone else, that the default position of NHS managers when things go wrong is the cover up. And I think they may find it quite hard to cover up criminal activities and I’m glad that they failed to get away with that.”

No doubt

Insisting there could be no doubt that the babies were harmed deliberately, Dr Evans said: “I think you need to keep it simple for a clinician. I couldn’t think of another cause. I was aware because the police were involved that some criminal activity was suspected, and I had to block that thought out, which was why I told the police not to name the suspect, even if they had a suspect.

“To use the jargon, I approached it in a very clinical way. I only had access to the notes. The notes were electronic copies, prepared by Chester NHS and given to the police. Many of the notes were organised disgracefully – not in date order, things were upside down, I had to print out a lot of them simply to make sense out of them. So both the police and I had to put up with shabby support from NHS management.

“But I looked at each case individually and I think certainly for the seven murder convictions and the convictions for attempted murder, each case in my opinion was a standalone case – in other words, if it was the only case I think there was sufficient to explore and investigate it from a criminal point of view and possibly charge someone. Were there only one or two cases, of course, it would be more difficult to prove who was responsible for the assault.”


Three months into the murder trial, Letby’s legal team applied to exclude Dr Evans’ evidence.

Ben Myers KC applied to trial judge Mr Justice Goss – in the absence of the jury – to strike out the evidence Dr Evans had given on seven babies and stop him returning to the witness box.

The barrister submitted that Dr Evans had failed to act with the independence, impartiality and objectivity required of such a witness.

However Mr Justice Goss refused the application and said it was for the jury “to determine, as with any witness, his (Dr Evans’) reliability, having regard to all the evidence in the case”.

Lucy Letby reacting to the final questions from her barrister Ben Myers, as she appears in the dock at Manchester Crown Court. Image Court artist sketch by Elizabeth Cook PA Wire

During the trial and under cross-examination from Mr Myers, Dr Evans was accused on several occasions of adopting a partisan approach to the case.

The barrister accused him of repeatedly “reaching for things to support the allegations rather than reflecting the facts” and said he was not independent.

In one exchange, Dr Evans said he found the suggestion “insulting”, adding: “I’m completely independent. I have been giving evidence in court for a long time. I know about impartiality. I know about the rules. I’m not here for the prosecution. I’m not here for the defence. I’m here for the court.”

The UK Government has ordered an independent inquiry into the circumstances behind Letby’s murders, looking at how clinicians’ concerns were handled.

Dr Evans is a long-time member of Plaid Cymru and in 2019 stood unsuccessfully to become the party’s national chair.

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Mab Meirion
Mab Meirion
10 months ago

A good man to have in our ranks…

10 months ago
Reply to  Mab Meirion

Shame the rank and file party membership didn’t cotton on to that fact when they had the opportunity to elect him to the Chair …. or was that opportunity denied by manipulation ? Evidence is in the history. Check how many people were allowed access to the voting procedure.

Mab Meirion
Mab Meirion
10 months ago
Reply to  hdavies15

A fly on the wall at a school reunion in Carmarthen maybe…

10 months ago
Reply to  Mab Meirion

I think it was held in a hall in Swansea with room for a few hundred only. Rest of card carrying membership were shut out of the procedure. Vintage Soviet era democracy.

10 months ago

Why or why didn’t PC elect him chair ? Been a disaster ever since !

Neil McEvoy – PC’s ONLY asset in the Capital gone !

Llanelli gone!

Carmarthen soon gone !

10 months ago
Reply to  Nia

Having a good day i see ❤️

Ymlaen at
Y dyfodol

Geoff Horton-Jones
Geoff Horton-Jones
10 months ago

A case of the right man being in the right place at the right time
Had events with Plaid been different this would not have happened
Dewi is a credit to this country of ours

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