The murder victim of girls aged 13 and 14 suffered more than 100 injuries after she was battered with a wooden stick, a TV set, a computer printer and a coffee table, a court has heard.
Angela Wrightson, 39, was subjected to a "sustained and brutal" assault before her half-naked body was found at her home in Stephen Street, Hartlepool, in December, Teesside Crown Court heard.
Nicholas Campbell QC, prosecuting, told the jury: "It was a Tuesday morning last December that the blood-stained body of a 39-year-old woman was found in her Hartlepool home.
"Angela Wrightson was found by her landlord. The body was sitting on a sofa in her front room, she was naked from the waist down."
The landlord dialled 999.
Mr Campbell said: "It became clear that Angela Wrightson had been the victim of a sustained and brutal assault.
"There were well over 100 injuries. The evidence at the scene of the crime showed she had been struck in 12 separate locations within that room.
"A number of implements were used as weapons. They included a wooden stick with screws standing proud of the surface, a TV set, a printer from a home computer, a coffee table and a shovel.
"Smaller items such as a kettle and a metal pan were used together with a glass vase and other ornaments."
The jury was told both girls, who deny murder and cannot be named in reports, were in local authority care at the time.
Now aged 14 and 15, the defendants had formed an "intense relationship", the court heard.
"The prosecution case is that they were in it together and that they are jointly responsible for this fatal act," Mr Campbell said.
The older girl, wearing a black and pink top and clutching a tracksuit top in court, denied intending to cause serious harm to Miss Wrightson, Mr Campbell said.
The younger girl, wearing a black cardigan over a white blouse for the hearing, claims she played no part in the assault and did not encourage her co-accused.
The younger girl took selfies at the scene of the crime after the violence had started and published one on Snapchat, the court heard.
One taken at 9pm showed her co-accused in the background, and further back, Ms Wrightson. Both girls were smiling, but the woman was not, Mr Campbell said.
And there were already marks on her face.
Later the younger girl contacted a friend using Facebook, jurors heard, and that witness went on to tell police that during the call she heard the defendant shout: "Go on (names older defendant), smash her head in, bray her, f***ing kill her."
The witness told police she thought she then heard laughing in the background.
The friend thought the defendant sounded drunk.
Further selfies that the younger girl took showed the girls drinking cider from a bottle.
The girls had let themselves in through Miss Wrightson's unlocked front door at around 7.30pm and left after 11pm, jurors heard. They came back at around 2am the next morning before leaving a final time at 4am.
Ms Wrightson may already have been dead by 11pm, the court was told.
Between 11pm and 2am they chatted with a local teenager who asked why they had blood on their clothes, jurors heard.
They told him they had both fallen over.
He heard the older girl say: "We have to get back to the house, check if she is dead."
Their victim was an alcoholic and in drink could be a nuisance, the court heard.
She allowed young people to drink in her house and would buy cigarettes and alcohol for them from a local shop.
The younger girl was staying with foster parents while the older one was in a local authority home, the jury was told.
The older girl had visited her mother on the day of the attack, the jury heard. "You will be hearing that theirs is not a constructive relationship," Mr Campbell said.
The girl was seen to be upset and when a relative asked why, she said her mother "had told her to go and kill herself", the court heard.
The defendants were close friends.
"It is the prosecution case that each was a bad influence on the other and at night, they would often run off together causing the police to be involved in bringing them back to their respective homes," Mr Campbell said.
"The night of the murder was such a night."
Around six weeks before the murder the younger girl sent the older defendant a message referring to her "little partner in crime", the court was told.