Blood from transgender teenager Brianna Ghey, who was stabbed 28 times in a “frenzied” knife attack, was found on the trainers and jacket of a boy accused of her murder, a jury heard.

The youth, identified only as boy Y because of his age, claims he came into contact with Brianna, 16, after seeing her being stabbed by his co-accused, girl X, and then checking whether she was still alive as she lay on the ground.

Boy Y and girl X, both now 16 but aged 15 at the time of Brianna’s death, both deny murder and are blaming each other for the stabbing, Manchester Crown Court heard.

Brianna’s blood was found on boy Y’s trainers and black ski-jacket, and on a hunting knife found in his bedroom at his home, the jury was told.

None of Brianna’s blood was found on the clothing of girl X, the court heard.

Brianna suffered un-survivable injuries to her head, neck, chest, back and sides in the “sustained and violent assault” after being lured to Linear Park in Culcheth, near Warrington on February 11.

Prosecutors have told the jury the pair planned to kill Brianna and, irrespective of who wielded the knife, both are guilty of murder.

Jane Roughley, a forensic scientist and blood pattern expert, who visited the scene and examined blood-stained items said her overall conclusion was consistent with Brianna being attacked at or near a bench, either sitting or standing, or near the top of some steps nearby, where her body was found.

And the blood pattern distribution at the area of the steps suggests Brianna was assaulted at a low level, or while she was close to the ground.

Miss Roughley said the amount of blood on the jacket boy Y was wearing was more than she would expect if he had simply touched her to see if she was still alive.

Richard Pratt KC, defending girl X, said boy Y’s suggestion that girl X had done the stabbing was “not realistic”, with no blood transfer to her clothing.

Mr Pratt continued: “If X used the knife 28 times, to not find it – extraordinary – not a drop of blood on her jacket. That’s what boy Y’s account is.”

Instead, he suggested girl X’s account, that boy Y inflicted the injuries, was consistent with the scientific evidence of no blood on her clothing.

Miss Roughley said the evidence does not point either way, as a wound can be inflicted without blood being transferred.

Mr Pratt continued: “What scientific finding is inconsistent with girl X’s account?”

Miss Roughly replied, “There are none.”

Richard Littler KC, defending boy Y, said, “You are being asked the scientific significance of no blood from Brianna Ghey being found on the red jacket (belonging to girl X).

“Have you been in cases where items have been washed? Sometimes washing away blood?

Miss Roughley replied: “In some instances, yes.”

Mr Littler suggested that at the beginning of knife attacks, there is less likely to be blood flowing freely and clothing a victim is wearing could soak up blood instead of it transferring to the attacker.

He asked: “So the absence of blood on somebody’s clothing may indicate they are not involved at all?

“It may also indicate they were involved at the time early on in an attack – putting a knife into someone’s body, an area of body that was clothed. All that could explain why the attacker could not get blood on her?”

Miss Roughley replied: “Yes.”

However, Joanne Millington, a forensic scientist and blood spatter analysis expert called by the defence for boy Y, said she disagreed with Miss Roughley’s findings.

Ms Millington said in her opinion, analysis of blood patterns “do not assist” in finding whether boy Y was either active in an attack on Brianna or had interacted with her body to check whether she was alive.

Earlier, the jury heard X and Y had a fixation with torture, violence and death and drew up a “kill list” of child victims.

An alleged “murder plan” to kill Brianna was found in the bedroom of X, who had an interest in serial killers, and she described herself as a “Satanist” the jury heard.

The trial continues.