Meet the barrister fighting to clear Lucy Letby's name

Times

a day ago

When Mark McDonald answered the phone, almost exactly a year ago, he had no idea he was about to step into the heart of one of the most high-profile cases in British legal history. The call was from Lucy Letby's parents and they wanted his help. 'A week later, I'm meeting Lucy,' McDonald recalls.
Letby's family wanted him to take over from her previous lawyer, Ben Myers, and free her from prison, where she is serving 15 whole-life terms. At the end of her ten-month trial in 2023 (one of the longest in British legal history) she was convicted of seven counts of murder and six of attempted murder at the Countess of Chester Hospital in Cheshire between 2015 and 2016. A further trial last year added one more conviction on a count of attempted murder. McDonald was Letby's last hope.
'I get the phone call when it's all gone wrong,' says McDonald, 59, a seasoned criminal defence barrister with a reputation for high-profile appeals. McDonald is in Devon on a family holiday, so we speak over Zoom. His two children, aged three and four, have spent all day building sandcastles and eating ice cream. But work never stops when it comes to McDonald's most high-profile client.
McDonald speaks to Letby, 35, once a week or every two weeks — sometimes more often — and visits her once a month at Bronzefield prison in Ashford, Surrey. He says Letby is 'in a very different place today than what she was 12 months ago'.
'Remember, 12 months ago, she'd lost every argument. She had been saying that she was not guilty right from the beginning and nobody believed her. She went through a whole trial and she was convicted. She went to the Court of Appeal and she was convicted. She had a retrial; she was convicted. She went to the Court of Appeal again; she was convicted. And that was it. There, you have a broken person. But today, after everything that has happened in the last 12 months, she's got new hope.'
At least some of that is thanks to McDonald. Back in 2023, under photos of her dead-eyed mugshot Letby was universally branded the blonde-haired, blue-eyed 'angel of death' who was 'evil' and 'a monster'.
Slowly at first and then all at once, the public debate over the veracity of her conviction became more heated. In the past 12 months McDonald has done everything he can to transform what was initially a tiny ripple of outlier conspiracy theorists decrying the nurse's guilt into overt support ranging from celebrities and newspaper columnists to scientists and some MPs.
But he still has a way to go. For Letby to be allowed to appeal against her conviction, McDonald must first submit 'new evidence' to the Criminal Cases Review Commission (CCRC), an independent public body that assesses potential miscarriages of justice.
To this end he has assembled a 14-strong independent panel of international neonatal and paediatric experts with whom he shared the babies' medical notes. In February, McDonald called a press conference in which they cast a shadow of doubt upon the prosecution's expert medical case. It caused a media storm. McDonald and his panel claimed to have assembled evidence to refute the sky-high insulin levels found in some of the babies ('the [insulin] test was not fit to be used as forensic evidence,' he says); the rota showing Letby was on duty (he says it 'doesn't stack up with statisticians'); and highlighted inconsistencies in the testimony of Dr Ravi Jayaram, who had claimed during the trial to have seen Letby standing over a baby with a dislodged breathing tube.
The parents of some of the victims say McDonald's 'publicity stunt' is 'distressing' and that they 'already have the truth'.
A BBC Panorama documentary last week raised concerns about McDonald's case. The documentary suggested there was a lack of consensus among the experts. In the case of Baby O, one expert, Dr Richard Taylor, claimed in a December 2024 press conference that the baby's liver was pierced with a needle by another doctor. However, another expert on the panel, Professor Neena Modi, claims the baby's liver injuries may have been caused by a traumatic birth.
The Thirlwall public inquiry was told Baby O was delivered by caesarean section and their medical records had no reference to any difficulties or trauma.
A defiant McDonald says the most recent documentary, by Judith Moritz and Jonathan Coffey, was 'a shambles' and he 'felt that much of it was wrong, misquoted' and 'poorly put together'. Moritz was one of the few reporters given access to the whole Letby trial at Manchester crown court and The Times's review called the documentary 'impressive' and 'a rigorous look at the evidence'.
However, what the panel do agree on is that Lucy Letby is innocent.
Heading the panel is the Canadian neonatologist Dr Shoo Lee, whose research paper on air embolisms in babies was referenced at Letby's trial. He says his research was misinterpreted and should never have been used. But the Court of Appeal dismissed his argument as 'irrelevant and inadmissible' because the babies had never been diagnosed like he claimed.
McDonald takes issue with the prosecution using the medical expert Dewi Evans — an expert paediatrician and former clinical director for paediatrics and neonatology — who he says 'has been retired for 14 years and wasn't even a neonatologist' — to convict Letby, but hasn't he done the same, cherry-picking his medical experts to counter Evans's opinion?
Many of the experts on his panel asked to see the medical notes under the condition that they could say publicly if they thought Letby was guilty, but all were in concurrence — no crime had been committed; Letby was innocent. Were there any experts who received the babies' medical notes and were not prepared to join the panel? 'No,' McDonald says.
He is also backed by the MP Sir David Davis and the former health secretary Sir Jeremy Hunt, who has said her case must be 'urgently re-examined'.
McDonald is so certain 'no crime has been committed' that he is working free. Although he has other (paid) work, he estimates he has spent thousands of hours on Letby's case. 'I can't tell you, every day I work on it,' he says. 'I'm on holiday in Devon and I'm working on it. I had a telephone conference with Lucy yesterday. I won't stop. I will not stop until she is out.'
McDonald says he can relate to the pressure of working in a hospital — it's where he started. He grew up in Birmingham and left school with no qualifications, becoming a general porter in a hospital aged 16, before becoming a plaster of Paris technician a couple of years later. Then he moved to the operating theatre as an assistant, and went to night school to study for A-levels that would lead him to study law at the University of Westminster. 'While I was at university studying law I continued to work all the time in the operating theatre. The last day of me working in the operating theatre was the day before my pupillage started as a barrister.'
He has worked with 'many intensive care nurses in my time' and 'assisted in operating on neonates, paediatrics and intubation — the whole lot'.
McDonald says he would have liked to have been Letby's lawyer from the start, and that 'I knew when she was arrested, I could write how this case would play out because I'd seen it before. I knew what was going to happen.'
Letby is not the first killer nurse McDonald has represented. He has launched appeals for Ben Geen, who in 2003 and 2004 was convicted of murdering two patients and committing grievous bodily harm against another 15 after he was found to be administering drugs so he could resuscitate the patients at Horton General Hospital in Banbury, Oxfordshire. Geen's appeals have failed.
I ask McDonald if he tends to see the best in people. 'Oh yeah,' he says as he runs a hand through his hair. 'I'm not naive; I'm a criminal defence barrister — I've represented many people over the years who are guilty. But I'm also able to see very clearly where this has gone wrong. There's no forensic evidence. There's no CCTV. There's no eyewitness evidence. There's just a theory by a man called Dewi Evans.'
The barrister's approach is not for everyone. McDonald doesn't deny he is a publicity seeker. He says when it comes to changing the public narrative in cases of miscarriages of justice, boosting the media profile is 'very important'. He says in such cases cases it is often 'important to win the public narrative' before winning 'the legal narrative, because the Court of Appeal will know that the country is going to be looking at them'. McDonald says when, not if, Letby's case goes back to the Court of Appeal, 'they're going to have to take notice of what's being said. The Court of Appeal will know that the country is going to be looking at them.'
Although McDonald is a master of public relations, he can be prone to exaggeration. 'If there was a poll tomorrow — obviously I haven't done a poll — but I would say that 50 per cent of the country would say that she needs to have a retrial because something's gone wrong, 40 per cent would say she's innocent and 10 per cent would say that we think she's guilty. I think it's that high.'
He says his family and friends have been supportive of his work with Letby, 'because, look, I'm right!' He catches himself, 'God, that sounds very arrogant, I don't mean it to, but I am. And that's not because I say I am, but because every international expert that's looked at this says I'm right.'
There is no time frame by which the CCRC must decide on whether to refer the case but McDonald expects it to be around the new year.
He says in his 26 years of being a barrister he has never submitted so much evidence to the CCRC and that 'there'd be public outrage' if it is not referred. He says: 'If this is not referred back to the Court of Appeal then one has to question the purpose of the CCRC.' He says there is 'no plan B'.
McDonald plans to do more paperwork on the case on holiday. He is talking to Letby again on Monday. What's driving him, he says, is that 'there's an innocent woman in prison that's been sentenced to the rest of her life to die in prison. And potentially I can get her out. It's not 'why am I doing it?' but 'why wouldn't I do it?''