Two girls aged 13 and 14 dropped a television on a frail woman as they "forcibly restrained" her while battering and torturing her to death, a court has heard.
Angela Wrightson, 39, was found dead in her blood-spattered living room by her landlord in December 2014, having suffered "well in excess of 103" injuries, including 80 to her face.
The two girls, who cannot be named for legal reasons, were said to have used a variety of weapons in the "sustained and brutal" assault on the victim, who was 5ft 4in and weighed six and a half stone.
During the sick attack in Hartlepool, County Durham, the pair also giggled and posed for selfies at the scene, described as "akin to a bomb site", a court has been told.
The violence was said to have taken place over five hours from the evening of Monday December 8 into the early hours of Tuesday December 9. It is not known when MsWrightson died.
The jury at Leeds Crown Court was told that the girls had let themselves into the alcoholic woman's home before beginning the attack, leaving for "time out", and then returning to the scene for a further two hours where they were to leave her body in an "undignified manner".
The girls, who are now aged 15 and 14, both deny murder.
Jurors were told that Ms Wrightson's blood, skin and hair were found on a number of recovered implements, some of which had been damaged in the attack.
They included a television, a computer printer, a shovel and a wooden stick with protruding screws.
Other items used included ornaments, a picture frame, a coffee table and a kettle.
Prosecutor Nicholas Campbell QC told jurors that the best friends, who had an "intense" relationship, had been "in it together".
He said: "A number of weapons had been used to cause at least some of the injuries. At least one of those weapons was swung overhead, resulting in blood being cast off onto the ceiling. Blood, skin and hair were noted upon a variety of implements recovered."
Ms Wrightson's scalp and ears bore evidence of 15 "slash" injuries while there were also injuries to her torso, back and to each of her four limbs.
Mr Campbell said: "There is evidence of Angela Wrightson having fought back, trying to deflect the sharp weapon or weapons used to hurt her. There was evidence too that she had been forcibly restrained."
The court was told that forensic scientist Dr Gemma Escott, who attended the scene, concluded that the attack had "progressed around the room".
Ms Wrightson was found in darkness, sitting half-naked on her sofa, with blood and broken furniture all over the living room.
Twelve separate areas within the room were identified where blows had been struck. Paramedics had to remove a heavy wicker coffee table that lay in front of her body.
Mr Campbell said: "Dr Escott is of the opinion that at least 25 blows were struck with these implements. The table, the television and the printer appeared to her to have been thrown at or dropped on Angela Wrightson."
The court was told that tracksuit bottoms and a pair of shorts that Ms Wrightson had been wearing when injured were found on the sofa, which showed she had bled and had lost control of her bowels.
Mr Campbell said both garments had been removed from her "in one movement" before she moved or was "placed" in the position she was eventually found.
After the attack, the girls - who were in the care of the local authority - are said to have phoned police, giggling in the course of the 4am phone calls, to request a lift home.
While in the police van, one is said to have taken a picture of her co-accused and posted it to social media site Snapchat.
The message alledegly read: "Me and (names older girl) in the back, on the bizzie van again", and showed one of the girls covering her face with a Parka jacket on her lap concealing the blood.
Both defendants admit they were present at the time the injuries were inflicted.
The older girl accepts that she struck Ms Wrightson but said she did not intend her serious harm.
The younger girl says she played no part in the assault and did not encourage her co-accused in any way.