A woman has been sentenced to three-and-a-half years in prison for killing a man charged with sexually assaulting young boys on the east London estate where they lived.
Sarah Sands, 32, was found guilty of the manslaughter of Michael Pleasted, 77, by reason of loss of control.
Pleasted, who had previous convictions, was on bail awaiting trial when he was killed at his flat in east London.
He was stabbed eight times and bled to death, the Old Bailey heard.
Judge Nicholas Cooke QC said it was a "truly exceptional case" as he reduced her sentence from seven years to three-and-a-half, taking into consideration her position as a single mother.
Sands, who was cleared of murder, had armed herself with a knife and carried out a "determined and sustained attack" on Pleasted at his flat in Canning Town, the court heard.
Pleasted, who also went by the name of Robin Moult, had 24 previous convictions for sexual offences spanning three decades.
He served sentences of between nine months and six years for sex crimes that included indecent assaults on a boys aged under 16 and under 14.
However, he was not on the sex offenders register as he committed his offences before it was introduced in 1997.
'No mob rule'
Sands, who has been in custody for the past 10 months, could be released on parole in 11 months.
The judge emphasised the case was "unique" as Sands had lost control rather than taken the law into her own hands and engaged in "vigilante conduct".
He said: "There must never be the slightest encouragement for mob rule."
The judge added: "This was a case in which the defendant promptly gave herself up to the police in a highly stressed state, never disputed responsibility for the killing as a matter of fact, did not take the opportunity to get rid of evidence and demonstrated remorse."
At the time of the attack, Pleasted was on bail awaiting trial at Snaresbrook Crown Court on two charges of sexual assault on two children aged under 13.
Officers were also investigating a further allegation he had abused a third boy.
During the trial, Sands told the court she had not intended to hurt Pleasted when she went to his flat with a knife, claiming instead she wanted him to admit to his crimes so his young accusers would not have to go to court.
Sands told the jury she was "frightened", adding: "It was not how it was meant to go. He was meant to listen to me".
However she said Pleasted "smirked" when he answered the door and told her the boys were all liars who had ruined his life.
During the trial, the judge said an inquiry was under way into the decision to bail Pleasted.