The older girl accused of murdering Hartlepool woman Angela Wrightson 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”, prosecutor Nicholas Campbell QC said.
The prosecution case is that both these defendants are guilty of murder.Nicholas Campbell QC
Psychiatrists for the prosecution and defence will give evidence, the trial at Teesside Crown Court 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.
A witness said she received a call on Facebook during which she heard the younger girl egging on the other defendant, and laughter.
The witness, a 15-year-old friend of the younger girl, had been messaged by the younger defendant to say she had been reported as missing.
They then spoke over the Messenger app and the witness said her friend broke off the conversation to say: “Go on (names the older girl).”
She then either said “bray her” or “smash her head in”, before finishing: “F****** kill her.”
In a video interview with police which was played in court, the witness said she then heard laughter down the phone.
She told the detective: “I thought (the older girl) might have been having a play fight.”