A 24-year-old man has been found guilty of murdering his best friend after stabbing him 37 times on Christmas Eve in the house they shared.

Dylan Thomas killed William Bush, 23, on 24 December 2023, a jury at Cardiff Crown Court decided.

Thomas, who admitted manslaughter but denied murder, had looked up details of the anatomy of the neck in the hours before the attack in Llandaff, Cardiff, armed with a large kitchen knife and a flick knife.

He had been arrested weeks earlier for trying to scale the fence at Buckingham Palace, and is being treated for schizophrenia at a secure hospital.

The jury went out to consider its decision on Thursday morning and returned its guilty verdict a few hours later.

The prosecution told the trial that Thomas was in a “downward spiral” but in control of his actions at the time of the killing.

The court heard that on the morning of the attack, Thomas’ grandmother, Sharon Burton, drove him to Llandaff, and she described him becoming “more and more agitated” and sending several text messages.

When she parked outside the property, Thomas went in, got the knives, went to Mr Bush’s bedroom and stabbed him repeatedly.

The prosecution said passers-by “heard screams of horror” from the house.

A distressed Thomas banged on his grandmother’s car window and she found Mr Bush on the patio outside.

Thomas claimed in a 999 call after the attack asking for an ambulance that his friend had “gone mental” and stabbed him.

But the prosecution told the trial it was “a planned attack,” by Thomas on Mr Bush, and he “deliberately armed himself with knives and attacked him from behind.”

The court was given expert opinion that Thomas had been psychotic for months before the killing.

Jurors heard that he told police officers he was Jesus after his arrest for the killing and offered one PC a “job with God”.

Following the earlier arrest at Buckingham Palace he spoke about the “illuminati” running the world.

The court was told that Thomas believed he could harness gravity and told police he was “exploring energy fields” when arrested at Buckingham Palace on 6 November 2023.

Dr Panchu Xavier told jurors that his patient was experiencing psychosis when he was admitted to Ashworth High Secure Hospital, Liverpool, in March 2024.

Thomas and Mr Bush had been friends since they met at school at Christ College in Brecon, Powys.

But Gregory Bull KC, prosecuting, told the court that while Mr Bush was popular, Thomas had few friends and was viewed as something of a loner.

Orlando Pownall KC, defending, had told the trial there was no question Thomas was psychotic, but said the dispute was over the timings.

Mr Pownall told jurors Thomas had been through “a lot of stressful situations” including his parents’ separation, and there was “alleged domestic violence”.