A man who killed his friend on Christmas Eve in Cardiff previously tried to break into Buckingham Palace, a court has heard.
Dylan Thomas, 24, is accused of murdering William Bush, 23, in a “frenzied attack” on December 24 last year at their home in Llandaff.
Thomas admitted manslaughter at a hearing last week but denies murder.
He appeared before Cardiff Crown Court via video link from a psychiatric hospital on Wednesday, wearing a grey jumper and trousers, with close-cut black hair.
William Bush died at a property in Cardiff in December 2023 (South Wales Police/PA)
The court heard that Thomas had previously been arrested for attempting to scale a 14-foot fence to break into Buckingham Palace.
The jury was shown a police video interview with Alexander Bush, the brother of the deceased, which took place on January 12 2024, a few days after the attack.
He said: “I asked how Dylan was, and Will had mentioned that he had been arrested in London for trying to climb into Buckingham Palace.”
He told the police he had initially laughed it off thinking his brother was joking.
“Will obviously knew it was serious,” he said, “Will described it as he was curious, he wanted to know what would happen.”
Will Bush’s girlfriend, Ella Jefferies, also told the police that Thomas had attempted to break into the palace, saying he had tried to climb a 14-foot fence.
She also told the police that Will Bush had told her Thomas had suggested he wanted to kill him a month or two before the incident, the court heard.
She said: “Will told me that Dylan had come into his room and told him ‘I have thought and/or wondered about killing you’.”
The comment scared Mr Bush, with Ms Jefferies saying he began “barricading” his door, the court heard.
“I wanted him to move out,” she said.
“I wasn’t comfortable with him being there.”
Both Mr Bush’s brother and partner described him as being a “loyal” and “caring” friend.
The jury heard that Mr Bush and Thomas had been friends since they were around 13 years old, having met at Christ College Brecon, a private boarding and day school in mid-Wales.
They began living together in Llandaff, at a home owned by Thomas’ grandparents, after Mr Bush finished university around the summer of 2021.
Gregory Bull KC, speaking on behalf of the prosecution, said it was Thomas’s case that he was “suffering an abnormality of mind” during the attack.
But the Crown argued that this was not the case and that Thomas had planned the attack.
Mr Bull described events leading up to the incident to the jury of 10 men and two women and said “screams of horror” could be heard from the street coming from the house during the attack.
The prosecutor told the court Thomas was driven to the house he shared with Mr Bush in Llandaff by his grandmother on Christmas Eve, telling her he wanted to walk his dog.
He said: “The next thing she knew was that a few minutes later, Mr Thomas was banging on her window plainly distressed.
“Screams described as screams of horror were heard by (a man) who was in the street.
“It is the prosecution case that Mr Thomas made his way into the property.
“He entered through the kitchen where he armed himself with a large kitchen knife and a black lock knife or flick knife.
“He then proceeded to go up the two staircases and into the room of William Bush.”
Thomas is accused of first using the flick knife to stab Mr Bush in the neck from behind, with the latter then trying to “flee for his life”.
The trial is being held at Cardiff Crown Court (Antony Stone/PA)
Mr Bull added: “It is clear that Dylan Thomas used the kitchen knife to stab Mr Bush in the chest and cut his throat, severing the major artery in the neck, as a result of which Mr Bush bled to death.”
A kitchen knife used in the attack, covered in blood, its tip bent at some point during the incident, was shown to the jury, as well as a black flick knife.
Thomas told the police he stabbed Mr Bush in self-defence, insisting his friend had been “having an episode”.
Leading up to the incident, the court was told Thomas searched on his computer for the anatomy of the neck and messaged Mr Bush telling him: “I need to see you before you go.”
Thomas sustained injuries to both hands during the incident, which he told the police happened while trying to disarm Mr Bush.
A video shown to the jury showed a police officer confronting Thomas on December 24, covered in blood, his hands out in front of him.
The police officer asked him, “where’s the person who did this?” and he replied, “I think he is dead, I f****** disarmed him”.
Mr Bull described Thomas as having few friends and was “something of a loner”, with his grandmother calling him a “quiet person”.
Thomas is expected to defend himself against the charge on the grounds of diminished responsibility.
Mr Bull said the prosecution accepted that Thomas was “mentally unwell” and prior to the killing on Christmas Eve had begun suffering from psychosis.
He said: “Following the killing, his condition worsened, as a result of which he has been receiving treatment for schizophrenia at the hospital.”
The jury heard that Thomas had suffered at least one previous hallucination, in which he believed Mr Bush had “threatened to drink his spinal fluid”.
He said two psychiatrists had examined Thomas and differed in opinion about whether the act was caused by psychosis, with Mr Bull arguing the “frenzied attack” was intentional.
He said: “The difference between the two doctors relates to what happened at the time of the killing.
“Mr (Dilum) Jayawickrama is of the opinion that when you look at the evidence as a whole, it demonstrates that this defendant did know what he was doing.
“It is the view of Mr Jayawickrama that even where a man is suffering from a psychotic illness, that does not necessarily mean that the psychosis has caused the act.”
The trial continues.