The grandmother of a man who killed his friend at the home they shared on Christmas Eve drove him to the property, a court has heard.

Sharon Burton took her grandson, Dylan Thomas, 24, to his house in Llandaff, Cardiff, where he repeatedly stabbed William Bush, 23, on December 24 last year, while she sat outside in the car unaware of the incident inside.

She told the police the first time she knew something had happened was when Thomas, covered in blood, began banging on her car window.

Mrs Burton then pushed by him to attempt CPR on Mr Bush, who had been stabbed 37 times, including to his neck and torso.

Thomas has admitted manslaughter but denies murder.

He appeared before Cardiff Crown Court by video link from a psychiatric hospital on Thursday, wearing a black jumper, with close-cut black hair, his hands clasped in front of him on his lap.

The jury was shown a police interview with Mrs Burton, recorded on the day of the incident, who wept as she recounted the events.

I just wished I had never taken him there, I never envisaged anything like that with Dylan because he’s such a quiet, reserved boy

“I took him to his house because he’s got a dog there and he wanted the dog to go for a walk,” she said.

“He said he would be 10 minutes, I got on the telephone to my youngest daughter.

“Within no more than five minutes, all I hear is my car window being banged on.”

She added: “He was screaming, and I don’t know now if he said, ‘he’s going crazy’ or ‘he’s gone crazy’.

“I took the car keys and jumped out and Dylan was just covered in blood, I ran to the house and I could see Will on the floor.”

She attempted to carry out CPR until the ambulance arrived, handing Thomas her phone to call the police and ambulance.

She added: “I felt in my heart ‘he’s dead’ but was praying he was going to be OK. I couldn’t stop.”

“I’m in a nightmare,” she told the officer.

“I just wished I had never taken him there, I never envisaged anything like that with Dylan because he’s such a quiet, reserved boy.”

Thomas, who is being treated for schizophrenia, argues the incident was manslaughter by means of diminished responsibility.

But the Crown, who accept Thomas is “mentally unwell”, said he had planned the attack, having searched for the anatomy of the neck ahead of the incident.

Mrs Burton told the officer her grandson had been restless the evening before the incident, and she had been “concerned” when he also appeared to completely forget about an event he and the family had attended in St Fagans two weeks before.

The court also heard that Thomas had begun talking about conspiracy theories, including about the Illuminati and witches, which his grandmother said “he believed”.

Dylan is a very calm person, he’s not loud, noisy, confrontational - never, ever known him to be. He’s very immature, as in young for his 23 years

The jury heard on Wednesday that Thomas had attempted to break into Buckingham Palace earlier in 2023, which Mrs Burton said the family was unaware of.

She described her grandson as being “young” for his age.

“Dylan is a very calm person, he’s not loud, noisy, confrontational – never, ever known him to be. He’s very immature, as in young for his 23 years,” she said.

The court was shown body-worn police camera footage of Thomas being led to the back of a police van following the incident.

He asked the officer to keep an eye on the police in his house, claiming the last time he interacted with the police they “tried to plant coke on me”.

Thomas said Mr Bush had been going “psycho for months” and that he had been telling his friend to leave the house.

He added: “It was f****** self-defence mate, he was coming at me and I stabbed him back.”

Thomas and Mr Bush had been friends since they were around 13, having met at Christ College Brecon, a private boarding and day school in mid-Wales, the court has heard previously.

They began living together in Llandaff, at a home owned by Thomas’s grandparents, after Mr Bush finished university around the summer of 2021.

The trial continues.