The Self-Appointed Expert Who Helped Convict Lucy Letby

Dewi Evans asked to be the ‘expert witness.’

The prosecution in the Lucy Letby trial will place enormous emphasis on testimony from their star witness, Dr Dewi Evans. Yet Evans himself is steeped in controversy. Many people, including Lord Justice Jackson, have questioned his ability to be an expert witness.

Crucially, Evans was never approached by the prosecution. Instead, he rang them and volunteered his services. He was keen to attach himself to a case of historic magnitude.

So did Evans behave as an impartial witness, or did he, like some police and media figures, bend facts to make himself a star while ruining an innocent girl’s life?

Background

Dr Dewi Evans began his medical career in the early nineteen seventies, qualifying MB BCh in 1971, followed by MRCP in 1975.

His early years were spent as a registrar at prominent paediatric centres, including Alder Hey Hospital. By the 1980s he had become a consultant paediatrician in Swansea, a post he held for three decades, caring for newborns and children.

Little is recorded publicly about his personal life. He retired from clinical duties in 2009 and forged a second career as an expert witness.

Beneath the credentials and courtroom confidence, lies a history of flawed judgment, misdiagnosis, and professional overreach.

A Pattern of Failure

Evans is no stranger to controversy. In 1989 nine-year-old Robbie Powell was admitted to Morriston Hospital. Symptoms included rapid weight loss, abdominal pain, vomiting without diarrhoea, dehydration, and dark skin pigmentation.

The three consultants on the case were Dr Dewi Evans, Dr William Forbes, and Dr Narendra Agarwal.

Dr Forbes suspected Addison’s disease, a life-threatening yet treatable condition, and ordered an ACTH test that was never carried out. Robbie’s parents were told he had gastroenteritis caused by a throat infection. His GP, however, was advised of the possible Addison’s diagnosis.

On 1 April 1990 Robbie became unwell again. Over the next fifteen days, he was seen seven times by five different GPs before being readmitted to hospital. He died on 17 April 1990, aged ten.

The investigation that followed uncovered medical cover-ups. Thirty-five criminal charges were recommended against six individuals, but the Crown Prosecution Service declined to proceed.

Dr Evans said he had no involvement in Robbie’s treatment. In a letter to one GP, he wrote, “One can but conclude that there are conditions in children that are virtually undiagnosable before it is too late. Certainly, I cannot think of any steps that you could have taken as the GPs which could have anticipated such an event.”

A Precursor to Letby

The case of Bonnie Lewis in the late 1990s is another warning sign. Bonnie, a twelve-year-old from Neath Port Talbot, suffered a prolonged undiagnosed illness. Doctors suspected appendicitis, removed her appendix, and left her with an abscess that almost killed her. After discharge her pain continued.

In July 1997 Evans attended a social services conference and declared there was nothing physically wrong with Bonnie, claiming her mother “has problems.” He diagnosed “attention seeking by proxy,” a term outside his expertise. This blocked further medical help.

In 1998 the family travelled to the United States, where Bonnie was diagnosed with Zollinger-Ellison syndrome. Social services, relying on Evans’s opinion, charged her mother with unlawful kidnapping and extradited her. Bonnie was separated from her mother, causing unknown distress. Although Bonnie was eventually treated, the episode remains mired in debate over Evans’s role.

Lord Justice Jackson

Lord Justice Jackson, a senior Court of Appeal judge renowned for reforming civil justice costs and procedure, has publicly criticised Evans.

In 2022 Jackson reviewed an Evans report in a family court appeal and called it “worthless,” saying it lacked any attempt at balance.

It is alleged that Jackson wrote directly to Mr Justice Goss, trial judge in the Letby case, warning that Evans forms conclusions first and then twists evidence to fit them. Such criticism from a judge of Jackson’s standing does more than undermine credibility, it destroys it.

“My Kind of Case”

Evans entered the Letby investigation in 2017, contacting the National Crime Agency uninvited.

If the Chester police have no one in mind, I’d be interested to help. Sounds like my kind of case.” — Dewi Evans

He reviewed post-mortem photographs and declared at once, “Oh my God. This baby has suffered trauma.” Police then gave him full medical records and relied on his views, though his background is general paediatrics, not neonatology.

Evans’s initial opinion shaped the Baby C allegation, yet later he told The Guardian he no longer held that view. He now thinks medical complications, not foul play, explain the baby’s condition.

What I had not realised — I don’t think any of us realised — was the delayed bowel action was a more important factor in causing the air in the stomach.

He helped convict a nurse then casually reversed his conclusion.

Practising neonatal specialists who have seen the same files do not share Evans’s conclusions. Even in Baby O, where the jury heard Letby had traumatised a liver, later review suggests the injury stemmed from an attempted resuscitation by Dr Stephen Brearey, a consultant who had promoted suspicions against Letby.

The 60 Minutes Interview

On 60 Minutes Australia Evans gave an inflammatory defence of the conviction. He called Letby “the worst female serial killer in English history,” claiming she stalked babies to kill them.

He acknowledged that no one saw her harm infants yet dismissed doubts, saying critics “need to go out a bit more.” Confronted with the absence of forensic proof, CCTV, or eyewitnesses, he maintained that clinical notes and police timing placed Letby at each crime scene.

Asked whether he feared being wrong, he replied, “No.” He ridiculed international experts such as Dr Shoo Lee, labelling their views “as weak a group of opinions as I have ever seen.” Critics became “sofa sleuths” and “Poundland Poirots,” and he insisted, “There is no new evidence, only new opinion.”

Not Impartial, Not Apologetic

Evans has always claimed independence.

I’m not here for the prosecution. I’m not here for the defence. I’m here for the court. — Evans

Actions tell a different story. His record shows clear bias, emotional involvement, and contempt for counter-evidence. When The Guardian raised his shifting stance on Baby C, he retorted,

Lucy Letby murdered Baby C. Get that into your head. — Evans

That is not expert testimony. That is dogma.

Evans stopped taking new cases in 2023, half a century after his first paediatric post. He leaves a legacy demanding scrutiny rather than celebration. Multiple interventions have led to misjudgments, wrongful separations, and potentially wrongful convictions. Judges have branded his evidence unreliable, one-sided, and speculative. He has reversed key testimony yet shows contempt for anyone who questions him.

This is the man who helped convict an innocent woman.

---

Want to know more?

Join me live this Friday at 8 pm (BST) on Coffee and Crime where I’ll be in conversation with

Author Ed Anderson

, breaking down every explosive detail of the Lucy Letby case.

Hit subscribe on Coffee and Crime so you don’t miss it. Trust me, you’ll want to hear this.