Mother, 39, is found guilty of murdering her adopted baby daughter more than a decade after child's death

•  Katie Tidmarsh is due to be sentenced tomorrow for the shocking crime
•  Baby Ruby Thompson died in August 2012 after suffering brain damage

A mother has been found guilty of murdering her adopted baby daughter – more than a decade after the child's death.

There were gasps in the public gallery as a jury found Katie Tidmarsh, now 39, guilty by majority verdict of causing catastrophic head injuries consistent with shaking and a 'high-energy impact' to Ruby Thompson in August 2012.

Jurors heard Ruby suffered brain damage which led to a cardiac arrest. She died two days after she was admitted to hospital.

Subsequent medical investigations revealed Ruby had a large skull fracture, as well as bleeding in the brain, the spinal canal, and both eyes – suggesting 'abusive trauma'.

Prosecutor Jonas Hankin KC said the infant had been taken into care from birth, and was adopted by Tidmarsh and her then husband just five months before she suffered fatal injuries while in her adoptive mother's sole care at home in Leicester.

The court heard that Tidmarsh had begun suffering from mood swings and bouts of depression and anxiety while going through the adoption selection process – but failed to mention her mental health issues to the adoption panel.

The defendant will be sentenced at Leicester Crown Court tomorrow.

Tidmarsh was arrested on suspicion of murder three months after her daughter died and was interviewed multiple times, telling police Ruby suddenly collapsed at home while being fed yoghurt. 

She claimed Ruby began rolling her eyes before falling backwards to the floor, striking her head and becoming lifeless – and may have received some of her injuries during CPR attempts following her collapse.

But Mr Hankin told jurors at Leicester Crown Court: 'Experts in a range of disciplines have examined the medical evidence and they are of one voice… the explanation given by the defendant of a minor low-level fall cannot and does not explain the nature and severity of the injury Ruby sustained or the mechanics required to cause them.

'The only plausible explanation for the totality of injuries and death in the absence of a reasonable explanation is an undisclosed assault inflicted immediately prior to, and causing, Ruby's collapse.'

Mr Hankin added Ruby had also suffered two fractures to her right arm in the months before her death, alleging they were also caused by Tidmarsh.

The court heard Tidmarsh and husband Michael, now 42, adopted Ruby in March 2012, seven years after they got married.

The couple were unable to have children and in 2009 decided to put their names forward for adoption. 

Mr Hankin said that a formal assessment began two years later – but around that time Tidmarsh visited her GP to say she was suffering from mood swings.

She made further appointments to say she was experiencing periods of depression and anxiety – with the adoption process given as a possible cause - and was prescribed antidepressants and diazepam, as well as being signed off work.

However, Mr Hankin said just weeks later Tidmarsh, now of Littlethorpe, Leics, met with the adoption panel and gave evidence about her medical history – but failed to mention her mental health issues.

He added: 'Based on the evidence it was recommended the adoption panel approved the decision to recommend them as prospective adopters.

'The prosecution say the defendant failing to disclose relevant, and what you may think important, information may be relevant to an ultimate assessment of her credibility.'

The court heard social workers initially believed Ruby seemed to have settled in well with her new family.

But Mr Hankin said 'the value of this observation is limited' by Tidmarsh's non-disclosure of her anxiety and depression, and an apparent failure to report an injury she later claimed Ruby had suffered which she used as an explanation for one of the arm fractures.

Jurors were told that on the day of Ruby's collapse, Mr Tidmarsh was mowing the lawn before an intended family visit to a farm park.

He later told police his baby daughter had been 'alert and happy' that morning – but after he had been in the garden for around 40 minutes his wife came running out with Ruby in her arms shouting, 'Ring an ambulance, she is not breathing'.

The court heard a police car arrived first, and the decision was made to take Ruby to hospital in it, rather than wait for paramedics to arrive.

Officers who responded to the couple's 999 call said Tidmarsh said she was 'hysterical', adding she later gave an account that she'd been feeding Ruby when she suddenly collapsed.

However, Mr Hankin said Tidmarsh's claims 'lacked credibility and plausibility', adding the opinion of medical experts was that Ruby had suffered injuries consistent with shaking and an impact on a hard surface.

Following her initial arrest, Tidmarsh was released on bail before being re-arrested and interviewed the following June.

She was released with no further action, but was rearrested and charged in July 2022 following a re-examination of the case.

Tidmarsh denied murder, an alternate charge of manslaughter, and two counts of inflicting grievous bodily harm.

Tidmarsh was also convicted of one GBH charge and cleared of the other.

Following Tidmarsh's conviction, Detective Chief Inspector Mark Sinski, the senior investigating officer, said: 'It has taken over ten years to get this case to court and reach a successful guilty verdict.

'We never lost hope in seeking justice for Ruby and the absolute determination and commitment from the investigation and prosecution team has been undeniably vital in today's result.

'The evidence presented to the court, evidence from some of top medical experts in their respective fields, proved that Ruby's head injury was caused by shaking and a high-energy impact and not from a low fall on to a thick rug as Tidmarsh had claimed.

'Tidmarsh has evaded justice since 2012 and will now be facing a lengthy sentence for her actions in taking the life of a young child, a child who was placed in her care to give her what was believed to be a better life.

'This has clearly been a very sad and tragic case and on reaching this verdict, I hope that Ruby can finally rest in peace.

'The case against Tidmarsh was reopened after a family court judge ruled in 2017 that she had inflicted the injuries that caused Ruby's death.

Additional expert medical evidence was then gathered by detectives before the Crown Prosecution Service authorised charges.