Revealed: Parents who murdered two children and tried to kill four more are half-brother and sister

Sarah Barrass, 35, was jailed for life on Tuesday. (PA)

A mother and father who murdered their two teenage sons and conspired to murder their other four children are half-brother and sister, it has been revealed.

Sarah Barrass, 35, and Brandon Machin, 39, were jailed for life on Tuesday having plotted to kill the children.

After court reporting restrictions were lifted during their sentencing, it can now be revealed that Machin is Barrass's half-brother and the father of the six children.

The couple's two eldest sons Blake, 14 and Tristan, 13, were found lying fatally injured on their bunk beds at home in Sheffield by police in May. 

A court sketch of Sarah Barrass, 34, and Brandon Machin, 37, flanked by security staff. (PA)

They had been strangled and suffocated by Barrass and Machin in an apparent effort to stop them being taken into care. 

The couple were today both jailed for life and ordered to serve at least 35 years behind bars.

According to MailOnline, the court heard that the two killers had come from a dysfunctional family and Machin had himself been taken into care when he was 14.

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The pair embarked on a sexual relationship when he came out of care. 

Social services had been involved with their family in the 1990s and concerns had been raised about the half-siblings developing a sexual relationship.

The court heard that the children did not know that Machin – who is Barrass’s half brother – was their father and had been told their father was dead.

The funeral of the two children murdered by Sarah Barrass and her partner. (PA)

Kama Melly QC, prosecuting, told the court: “Both (the older children) are emotionally broken and don’t know why this happened. They repeatedly ask why and how. We don’t have the answers.”

The barrister added: “Both (the older children) keep saying they just want a nice family home.”

Mr Justice Goss said: “The statement from their social worker on their behalf describes their inevitable confusion, the effect of the loss of their brothers.

“Inevitably they will require a considerable amount of support. The long-term consequences to them and (the younger children) as they grow older cannot be known.”