Sarah Sands
Sarah Sands was jailed for three-and-a-half years for manslaughter Metropolitan Police

A mother-of-five has been sentenced to three-and-a-half years in prison for killing a man who was facing charges of sexually abusing young boys. Sarah Sands, 32, was cleared of murdering 77-year-old Michael Pleasted, but she was found guilty of manslaughter by reason of loss of control.

After hearing her neighbour had sexually assaulted three children, Sands armed herself with a knife on 28 November 2014. That same evening, Sands carried out a "determined and sustained attack" on Pleasted at his Canning Town flat in east London, the court heard. Pleasted was stabbed eight times and bled to death.

Sands then turned herself into the police and asked an officer: "Who houses a f*****g paedophile on an estate, like, seriously? He was, like, asking for trouble." She added: "He's f*****g harmless now, ain't he?"

Pleasted – also known as Robin Moult – had previously been convicted 24 times for sexual offences over a period of three decades (1970 to 1991), and had served sentences ranging from nine months to six years. The offences included indecent assault on a male over 16, indecent assault on a male under 16, indecent assault on a male under 14 and buggery. Pleasted was not listed on the sex offenders register because he had perpetrated the crimes before the introduction of the index in 1997.

Judge Nicholas Cooke QC took Sands's position as a single mother into account and called it a "truly exceptional case" as he halved her sentence from seven years.

During the trial, Sands said she had not intended to hurt Pleasted, but instead wanted him to admit to the crimes to spare his young accusers from going to court. "It was not how it was meant to go. He was meant to listen to me," she told the jury. Instead, Sands said Pleasted ignored her and "smirked" when he answered the door, saying the boys were all liars who had ruined his life.

Sands has been in custody for the past 10 months and could be released in 11 months. The judge said the case was an example of loss of control rather than "vigilante conduct". He 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."