A pair of siblings in the United Kingdom made headlines last year when authorities discovered that the two were actually involved in a sexual relationship and, in addition to killing two of their own children, had planned to kill all six of their offspring in order to keep their relationship a secret.
Sarah Barrass and Brandon Machin were each handed a minimum sentence of 35 years behind bars in November for the murders of two of their sons, 13-year-old Tristan and 14-year-old Blake, in May 2019, BBC News reported.
The second season of “Killer Siblings,” an Oxygen series that explores other murderous siblings, premieres on November 7 at 6 p.m. ET/PT on Oxygen.
Barrass and Machin were half-siblings as well as co-parents, a secret that the pair wanted to keep so badly that they murdered their own children.
Barrass and Machin first forced the four oldest children to take an abundance of medication that had been prescribed to treat ADHD, in the hopes that an overdose would kill them overnight, local newspaper, The Sheffield Star reported.
When that didn't work, the couple switched tactics. Barrass, after researching ways to murder someone online, strangled Tristan with a clothing sash, and Machin used his hands to strangle Blake, according to BBC News. They then put plastic bags over both boys' heads to make sure that they died, before moving on to trying — and failing — to drown one of the younger children in a bathtub.
The brutal act was reportedly an attempt by Barrass and Machin, who had been involved in a secret sexual relationship for several years, to keep their coupling a secret, BBC News reported.
A social worker had been assigned to the family, and two days before the murders, had informed Barrass that the family’s status would be updated from “child in need” to “child in protection,” which would result in greater involvement from the authorities, according to The Star.
Officials' increasing investigation into the family reportedly scared the parents. During the couple's sentencing hearing in November 2019, Prosecutor Kama Melly QC (Queen's Counsel) said that the couple came up with a plan to kill the children because they wanted to stop anyone from discovering the truth of their parentage.
“[Barras] said the social worker got too close to finding out that Brandon was the father to all of the children,” Melly said, according to The Star.
The children’s true parentage was a closely-kept secret, and the children had been told that their father had died while fighting in World War 2, The Guardian reported. And to onlookers, Machin was simply a supportive brother to Barrass, a single mother.
After Barrass and Machin killed Tristan and Blake and failed to kill a third child, Barrass retreated to a bedroom with the surviving children and got to work on another plan: blaming Machin for her eldest sons' deaths, according to The Star. She wrote multiple text messages claiming that Machin had killed the boys and was planning to kill her and the rest of the children.
“Brandon is the dad to all the kids...the pills didn’t work so he’s had me kill Tristan, and he’s killed Blake and [a third child], I’m sat here with the other three,” she wrote in one message, according to the prosecution.
“He’s going to kill them, then me,” read another.
She also messaged one friend, “He’s trying to kill us and Tristan and Blake are already dead.”
Barrass and the friend then both called the police. When authorities arrived at the house in Shiregreen, Barrass first claimed that her other two children were with neighbors, but one of the children was able to signal to a police constable that they were dead, according to The Guardian.
Barrass eventually admitted that she'd given the four oldest children a "cocktail of medications," and both her and Machin were arrested, The Star reported. Machin admitted to killing the children and said that Barrass was not involved.
Barrass initially tried to blame her half-brother (and lover) for the murders and said that he'd forced her to participate, but she later admitted that they'd come up with the deadly scheme together, according to The Star.
During proceedings, Bryan Cox QC (Queen's Counsel) claimed that Barrass, his client, had been "profoundly damaged" by her upbringing and was "desperate" to save her children from being put into foster care, BBC News reported.
Barrass and Machin both pleaded guilty in September 2019 to two counts of murder, conspiracy to murder six children, and five counts of attempted murder, The Guardian reported. They were sentenced in November to a minimum of 35 years each.
The surviving children have been left to deal with the trauma of witnessing their siblings die at the hands of trusted adults. One is afraid that they will become a killer too when they grow up; another sibling, who Barrass and Machin tried to drown in the tub, is now afraid of baths, according to online newspaper The Independent.
“Two of the surviving children witnessed their older siblings being attacked," Edmund Hulbert, of the Crown Prosecution Service, said, adding that "the trauma that all the children have experienced, and will continue to experience, is unimaginable.”
For more cases like this, watch the second season premiere of “Killer Siblings,” airing Saturday, November 7 at 6 p.m. ET/PT on Oxygen.
Crime Time is your destination for true crime stories from around the world, breaking crime news, and information about Oxygen's original true crime shows and documentaries. Sign up for our Crime Time Newsletter and subscribe to our true crime podcast Martinis & Murder for all the best true crime content.