The sudden death of consultant Mark Deakin has brought renewed attention to his complicated connection to convicted killer nurse Lucy Letby, after the married father-of-two was identified following the lifting of reporting restrictions that had protected his identity during her trial.

Deakin, 53, was found in his car in June, just one day after he had been dismissed from his position at Alder Hey Children’s Hospital in Liverpool. He was taken to hospital and placed in intensive care, but despite efforts to save him, he died nine days later.

His identity had previously been protected while Letby faced prosecution over the deaths and attempted killings of babies at the Countess of Chester Hospital. With the reporting restrictions lifted following his death, details of his professional and personal involvement in the case can now be reported.

Deakin had worked alongside Letby during the period between June 2015 and June 2016 when a series of infant deaths and serious collapses occurred on the neonatal unit at the Countess of Chester Hospital.

He was among the medical staff who interacted with Letby during that period and later supported her after she was removed from the neonatal unit amid concerns about the growing number of babies who had died or suffered unexpected medical emergencies.

The relationship between the consultant and Letby became a significant feature of the prosecution’s case. Prosecutors described Deakin as Letby’s boyfriend and argued that she was infatuated with him. They suggested that her desire to attract his attention could have provided a motive for some of the incidents involving vulnerable babies.

According to the prosecution case, Letby allegedly created medical emergencies knowing that Deakin would be contacted and would respond to the crisis. Prosecutors argued that she knew he would be bleeped and would rush to the neonatal unit to help treat a deteriorating infant.

Letby rejected the suggestion that she was in love with Deakin. She described him as a trusted friend rather than a romantic partner.

Despite that denial, their communications showed that they were close. Letby referred to Deakin as “sweetie” in messages, while notes discovered at her home included references to him as her “best friend” and “love.”

The pair exchanged more than 1,300 Facebook messages, and some of their communications later came under scrutiny because they included information relating to babies in the hospital’s care.

One of the most sensitive issues involved Baby N, a premature boy whose care was discussed in messages between Letby and Deakin.

Letby was convicted of attempting to murder Baby N the day after he was born in 2016. Prosecutors alleged that the nurse deliberately interfered with the baby’s care, forming part of the wider pattern of attacks for which she was ultimately convicted.

Deakin later became involved in proceedings examining how information about babies was handled. He was brought before a disciplinary hearing in June over a series of inappropriate texts exchanged with Letby during the time they worked together.

The communications included confidential details about the care provided to Baby N, raising questions about how information about patients had been shared.

Deakin later acknowledged that he had been misled by Letby and suggested that he may have been manipulated. During the Thirlwall Inquiry in 2024, he said he had been tricked into giving her information about babies she had attacked.

His comments offered a different perspective on the relationship that prosecutors had presented during Letby’s trial. While the Crown had emphasized their closeness and suggested that Deakin’s attention was important to Letby, Deakin’s later account indicated that he did not fully understand what was happening around him at the time.

He had also been questioned about what he knew regarding concerns raised by colleagues about Letby and the unusual number of infant deaths.

It was found that Deakin likely knew that colleagues had raised concerns about Letby’s possible connection to the spike in deaths. Those concerns became increasingly important as investigators attempted to understand what had happened on the neonatal unit.

Letby was eventually convicted of murdering and attempting to murder a number of babies. The charges involved children identified in court by letters rather than their names.

Her convictions included the murder of Child A, with prosecutors alleging that she injected air into the baby’s bloodstream. She was also convicted of attempting to murder Child B, the twin sister of Child A.

Child C and Child D were among the other babies involved in murder charges on which Letby was convicted. Prosecutors alleged different methods had been used in the attacks, including interference with feeding and the injection of air.

She was also convicted over the death of Child E and the attempted murder of Child F, twins whose cases involved allegations that Letby deliberately caused serious medical harm.

Child I was another murder conviction, while Child K became the subject of a later retrial after the original jury could not reach a verdict on the attempted murder allegation. Letby was ultimately convicted of that charge following the retrial.

She was also convicted of attempting to murder Child L and Child M, as well as one of the allegations involving Child N. The original jury could not reach verdicts on two other allegations relating to Child N.

The cases involving Child O and Child P resulted in further murder convictions, while the jury could not reach a verdict on the attempted murder allegation involving Child Q.

Letby’s convictions resulted in her being imprisoned for the rest of her life. She is currently held at HMP Bronzefield in Surrey.

During her original trial, Deakin gave evidence from behind a screen because of the reporting restrictions surrounding his identity. His appearance in the witness box was an emotional moment for Letby, who broke down in tears as he gave evidence.

The significance of their relationship continued to be examined after the trial. The Thirlwall Inquiry, established to investigate the circumstances surrounding the deaths and the wider handling of concerns about Letby, examined the actions and decisions of medical staff who worked around her.

Deakin’s own career continued after his time at the Countess of Chester Hospital. He had been appointed as a specialist diabetes consultant at Alder Hey in July 2018.

That appointment came shortly after Letby’s first arrest on July 3, 2018, an event that eventually led to the criminal investigation that resulted in her convictions.

But Deakin’s professional difficulties did not end with the conclusion of Letby’s trial.

In January 2024, around five months after Letby was convicted, bosses at the NHS Trust informed him that an investigation into his conduct had been launched.

The investigation focused on his conduct and communications, including issues surrounding the sharing of confidential information. The proceedings ultimately led to his dismissal from Alder Hey.

Deakin was found in his car the day after he was fired in June. He was rushed to hospital and placed in intensive care, but died nine days later.

His death has now placed his involvement in the Letby case under renewed scrutiny, particularly because his identity had remained protected during the criminal proceedings.

The circumstances of his death are separate from the convictions against Letby, and his professional disciplinary proceedings were also distinct from the criminal allegations against the former nurse. Nevertheless, the timing has drawn attention because his dismissal came after years of scrutiny connected to his dealings with Letby.

The story of Deakin and Letby highlights the complex web of relationships surrounding one of Britain’s most notorious criminal cases. Their thousands of messages, his evidence from behind a screen and his later admission that he may have been manipulated all became pieces of a much larger investigation into what happened at the Countess of Chester Hospital.

For investigators and the Thirlwall Inquiry, questions about communication between medical staff and Letby have formed part of a broader examination of whether warning signs were missed and whether concerns about unusual infant deaths were acted upon quickly enough.

For Deakin, those questions followed him long after he had left the hospital where he had worked with Letby. His career continued, but his connection to the former nurse remained part of the scrutiny surrounding the case.

His identification after his death means that the public can now understand more fully the role he played in the story, from his close friendship with Letby and the messages they exchanged to his evidence during her trial and his later account that he had been misled.

Letby’s convictions remain the central focus of the case, but the events surrounding those convictions continue to raise questions about professional responsibility, patient confidentiality and the relationships between staff members during the period when babies were dying and unexpectedly collapsing.

Years after the first concerns emerged, the consequences are still being felt by those who worked at the hospitals involved. Deakin’s death adds another tragic and deeply personal development to a case that has already left an enduring impact on the families of the babies, the medical professionals involved and the wider healthcare system.