Teenage boy accused of murdering Brianna Ghey told police he was ‘playing along’ with the ‘fantasy’ of a girl who boasted about already having killed people, court hears

A boy accused of luring Brianna Gay to her death in a park told police he “played along” with a “fantasy” created by a teenage girl who bragged about having killed people before, a court heard today.

But the 16-year-old, who can only be identified as Boy Y, agreed the “joke” had “gone too far” when Brianna was stabbed 28 times and left to die face down in the dirt, a jury was told.

The boy, who was 15 at the time, admits to bringing a hunting knife with him when he and his co-accused Girl X arranged to meet 16-year-old Brianna, who was transgender.

However, he denies inflicting the fatal wounds, claiming he turned away for a moment before seeing Girl X, also 15 at the time, hit Brianna “at least three times” before the pair fled.

Boy Y and girl X, who are said to have been fascinated by torture, violence and death, deny killing Brianna at Culcheth Linear Park near Warrington, Cheshire, on February 11.

Brianna Gay died aged 16 when she was stabbed 28 times in Culcheth Linear Park near Warrington, Cheshire, on February 11.

Brianna Gay died aged 16 when she was stabbed 28 times in Culcheth Linear Park near Warrington, Cheshire, on February 11.

Brianna, wearing a pink dress with a purse slung over her shoulder, is pictured with her mother Esther.

Brianna, wearing a pink dress with a purse slung over her shoulder, is pictured with her mother Esther.

Home Office pathologist Dr Alison Armor told the jury that Brianna (pictured) was the victim of a

Home Office pathologist Dr Alison Armor told the jury that Brianna (pictured) was the victim of a “sustained and brutal attack”.

Brianna’s supposed handwritten “murder plan” was later found in the bedroom of Girl X, who was obsessed with serial killers and called herself a “Satanist”, the trial heard.

Click here to listen to The Mail’s new podcast, The Trial.

The Trial takes listeners into the headlines and courtrooms of some of the world’s largest trials.

The first series, The Trial of Lucy Letby, was a worldwide hit, with more than 13 million downloads, and the second series focused on the murder of Ashling Murphy, a 23-year-old teacher from Ireland.

Season three follows the tragic case of Brianna Gay, a 16-year-old transgender girl who was murdered in Warrington, England.

Follow the evidence as the jury hears it in twice-weekly reports from The Daily Mail’s northern correspondent Liz Hull and broadcast journalist Caroline Cheetham.

Details of the injuries that caused Brianna’s “catastrophic blood loss” were told to a jury at Manchester Crown Court today by the Home Office pathologist who carried out the post-mortem.

It took about two hours to detail the location of the injuries using computer images.

Dr Alison Armor said the schoolgirl was the victim of a “sustained and brutal attack” and suffered stab wounds that would have required “considerable force” to inflict.

She said the stab wound alone would have been enough to prove fatal.

According to Dr Armour, the injuries were “consistent” with Boy Y’s 12cm (4¾in) hunting knife, which was found with Brianna’s blood in his bedroom after his arrest the following evening.

Richard Pratt, defending Girl X, asked her if it was “fair to say they also require significant force?”

“Someone pretty strong,” he added.

Dr. Armor replied, “It takes a certain amount of strength, I accept that.”

Girl X told boy Y that she had previously killed two people when they exchanged messages about a list of five children they wanted killed, the court heard.

When their first alleged target blocked Instagram messages from Girl X, the couple allegedly turned their attention to Brianna, who she became “obsessed with.”

In further police interviews played to the jury today, boy Y, who was diagnosed with autism after his arrest, the court heard, said he believed Girl X was “kidding” in reports about Brianna’s murder.

He said online chats about people she supposedly killed before were his way of “playing along with this fantasy”, saying he wrote things “that I don’t really believe” in order to “fit in”.

“She likes to make up a lot of stories and stuff,” he said.

When asked about Girl X’s comment that he was going to “research Chinese torture,” Boy Y responded that he liked to know “how they used to punish people” by studying history.

CCTV footage shows Brianna boarding a bus as she makes her final journey to the park in Culcheth.

CCTV footage shows Brianna boarding a bus as she makes her final journey to the park in Culcheth.

Police at the scene at Culcheth Linear Park in Warrington following the death of Brianna Gay.

Police at the scene at Culcheth Linear Park in Warrington following the death of Brianna Gay.

Police and forensic experts at Linear Park in Culcheth, Warrington, where Brianna's body was discovered.

Police and forensic experts at Linear Park in Culcheth, Warrington, where Brianna’s body was discovered.

When asked why he referred to Brianna as “she” in one message, Boy Y responded that he and his friends were “making gay jokes.”

But he insisted: “I don’t really care whether someone is gay or not.

“They make me feel like I’m doing it.”

In a police interview two days after Brianna’s death, Boy Y was asked, “At what point did it stop being a joke?”

Boy Y responded, “If I saw her carrying a knife, I would doubt it.”

The officer said, “You’re talking about taking a hunting knife with you.”

Boy Y replied: “I don’t know how to judge what jokes are. I think I’m going too far with jokes.”

Officer: “Do you think this joke has gone too far?”

Boy Yu: “Yes. I see it now. But I didn’t notice it then.

He said he tried to “appease” Girl X by saying he thought she was “making up stories” as she said she was “writing a book.”

“I don’t believe anything she says,” he added.

Earlier, Dr Armor told the jury that Brianna’s cause of death was multiple stab wounds “to the chest, neck, head and sides of the body”, penetrating the heart and both lungs.

Prosecuting Dina Heer K.S. asked the pathologist whether Boy Y’s hunting knife, purchased while skiing, was “a candidate for causing some or all of these wounds.”

“Yes, it is,” Dr. Armor replied.

Brianna's mother Esther (left) arrives at Manchester Crown Court on the first day of her murder trial.

Brianna’s mother Esther (left) arrives at Manchester Crown Court on the first day of her murder trial.

Brianna's father Peter Spooner walks into court in a black jacket, holding his partner's hand.

Brianna’s father Peter Spooner walks into court in a black jacket, holding his partner’s hand.

She said she could not rule out the possibility that another knife of the same size may have been used to inflict the wounds, but there was no conclusive evidence to suggest a second knife was used.

Girl X, now 16, from Warrington, followed the pathology evidence via video link to the secure unit where she was being held and appeared to take notes.

Trial judge Ms Justice Yip told the court that Boy Y was at the courthouse but asked not to come to court to obtain pathology evidence.

The judge said she had to carefully consider the involvement of both defendants and was advised this was the best way to deal with boy Y, who is from Leigh, Greater Manchester.

Both defendants deny murder.

The trial continues.