A 14-year-old girl killed a "dirty paedophile" who she said had abused her, the Old Bailey heard.
She and a 14-year-old boy stabbed suspect Robert Daley, 45, after the Crown Prosecution Service decided to drop the case, jurors were told.
The girl had complained to police, along with her 16-year-old sister and a woman, saying Mr Daley had sexually assaulted them.
But she had not made a statement. Prosecutors then decided that no charges should be brought in relation to any of the allegations.
After her arrest, the girl said she had first been abused by Daley at the age of 12 but it had been a year since he last sexually assaulted her.
"She called Robert Daley a dirty paedophile," said Jonathan Rees, QC, prosecuting.
She told police that she and the boy had gone to the man's house to "hustle" him for some money.
When she was in the kitchen, he had "started to grope her".
The boy came in, picked up a knife, and stabbed him a few times but Mr Daley would not let go and tried to reach for a weapon himself so the boy stabbed him again, the girl claimed.
She said she was "scared and frightened" and covered in blood and later threw the blade into bushes and burnt her clothes.
The girl had allegedly told a friend: "He tried to touch me again and I stabbed him."
She told a family friend that the man "tried to rape her so she stabbed him", said Mr Rees.
He said Mr Daley was told the accusations had been dropped on the day he died. He had denied all the claims.
Mr Rees said: "This phone call acted as a catalyst in his death."
Mr Daley had telephoned the 16-year-old and received a text back saying: "Stop calling and texting me. I really don't want anything to do with you. You are a perverted man and I can never forgive you."
It is alleged that the teenager rang the two defendants and they made their way to Mr Daley's home in Stockwell, south London.
Mr Rees said that five minutes after they arrived, Mr Daley had been stabbed five times in the side - two of them piercing his heart.
The boy and girl, who cannot be named for legal reasons and who are now both 15, deny murder on April 23.
Mr Rees said the boy was understood to be claiming that he used the knife while trying to defend himself and the girl.
Mr Rees said that despite their complaints to police, all three females continued to have contact with Mr Daley.
"In the months leading up to the death, relationships were far from straightforward," said Mr Rees.
"Although both girls made sexual allegations, it did not prevent them asking for assistance.
"It may be that relationships were relatively cordial in the weeks before the murder."
Mr Daley's friend said they all had dinner together and were getting on well, the jury heard.
The trial was adjourned to tomorrow.Reuse content