A teenage girl has admitted killing Angela Wrightson in her Hartlepool home.
But the defence barrister for the 15-year-old girl, who was 14 when Angela was battered to death, will argue she is not guilty of murder as she has “an abnormality of her mental function”.
The jury heard yesterday that Angela had 80 injuries to her head and tried to defend herself and was even restrained during the attack.
The living room in Angela’s home was like a “bombsite” when the first paramedic arrived and there was blood and broken furnishings all over the room, Teesside Crown Court heard.
The 39-year-old victim had suffered more than 100 separate injuries and died from either concussion, blood loss of a mixture of both, the court heard.
There was evidence she had tried to defend herself, and that she had been restrained, the jury was told.
The defendants, who were 13 and 14 at the time of the murder, deny the offence.
The older girl has admitted manslaughter, the jury was told.
The defence will argue she is not guilty of murder as she has “an abnormality of her mental function”, Mr Campbell said.
Psychiatrists for the prosecution and defence will give evidence, the trial was told.
Both agreed that at the time of the killing she had an abnormality, but differed about how bad it was. At issue will be her ability to understand her conduct, to form rational judgment and to exercise self control.
Mr Campbell said when she was arrested, the older girl said: “What the f***? I don’t understand.”
Interviewed by police, she admitted being at Ms Wrightson’s house and told detectives the woman’s face was already bloodied and was mumbling about someone called Julie.
The girl said Ms Wrightson was “OK” when they left her.
Police found pictures she had drawn of a woman stabbing a man, and she said she had been encouraged to “put those thoughts on paper and this had helped her manage her anger,” Mr Campbell said.
The other defendant was tearful when she was arrested and asked if her friend had been “locked up as well”, the court heard.
She told the police station custody officer: “I will admit I was in the vicinity, I didn’t murder her, I just sat there.”
The younger girl told police when they went round Ms Wrightson had two black eyes, and said they drank cider together.
There was a disagreement, and Ms Wrightson told them to “f*** off”, she told detectives.
The other girl then picked up the table and used it “to whack Angela over the head”, the younger defendant told police.
She said she told her friend to “behave” but the argument continued, and the other girl booted Ms Wrightson in the face.
In her interview, she said Ms Wrightson armed herself with a knife, so she intervened before her friend pushed the adult to the floor.
She said her friend broke a mirror then smashed up the rest of the room.
They “got bored” and went for a walk, and when they returned she claimed Ms Wrightson swore at them, which set her friend off again.
She told police that her friend used a table to hit Ms Wrightson over the head.
As they left, the girl claimed, Ms Wrightson was still telling them to “f*** off”.
A blood spatter expert found that both girls had struck blows, Mr Campbell said. “The prosecution case is that both these defendants are guilty of murder,” he said. “The prosecution case is that both the defendants were in this together.”
n Pathologist Dr Mark Egan weighed Ms Wrightson’s dead body and found she was just six-and-a-half stone and was 5ft 4in-tall.
He reported there were 80 injuries to her head alone.
Examination of her hands and arms show evidence she tried to deflect blows, Mr Campbell said, and that she had been “forcibly restrained” at times.
The amount of damage caused “would take a considerable time to inflict”, the pathologist found.
The jury has previously heard that the younger girl took a photo of the other defendant in the back of a police van they had called to give them a lift home after the murder, then shared the image on Snapchat.