Under the Banner of Heaven: Harrowing true story explained

The seven-part series features a cast including Andrew Garfield, Daisy Edgar-Jones, Wyatt Russell and Sam Worthington, and tells the harrowing true story surrounding the deaths of Brenda Lafferty and her daughter Erica.

Brenda, 24 years old, and her 15-month-old daughter Erica were brutally murdered in their home in American Fork, Utah, in 1984, in an incident which has since been detailed by Jon Krakauer in his 2003 book Under the Banner of Heaven: A Story of Violent Faith.

The book, which also explores the history of the Mormon religion, including its various radical factions, has been criticised by The Church of Jesus Christ of Latter-day Saints, which described the book as "not only a slap in the face of modern Latter-day Saints, but also a misrepresentation of religion in general".

Read on for everything you need to know about the true story behind Under the Banner of Heaven.

Under the Banner of Heaven true story explained

Brenda, a confident, spirited woman who was a broadcast journalism major and had aspirations of becoming a news anchor, was strangled and stabbed to death at the age of 24. She was found lying in a pool of her own blood in the kitchen by her husband Allen, who was at work when the killings took place.

Erica had also been stabbed and was discovered slumped in her crib.

It was Allen's brothers, Ron and Dan, who carried out the killings.

They were Mormon fundamentalists, and Ron claimed he had received a revelation from God to "remove" Brenda and her child.

Initially, the brothers belonged to The Church of Jesus Christ of Latter-day Saints but were excommunicated for their increasingly radical views – Dan first, followed by Ron – which prompted them to form their own sect, the School of the Prophets, in 1984.

They both believed in polygamy, citing it as one of the core tenets of the faith. They were allegedly inspired by Joseph Smith, the founder of Mormonism in the United States, who had vast numbers of wives – between 30 and 40, with one as young as 14-years-old (via CNN).

Polygamy, which is illegal in the US and was prohibited by the church in 1890, is still practiced by various offshoots of the religion. To avoid arrest, men will legally marry one wife and have multiple spiritual wives.

Under his new way of life, Dan's wife Matilda was forbidden "to drive, handle money or talk to anyone outside the family when Dan wasn't present". Their children were also taken out of school and the family was ordered to refuse modern medical treatment. Refusal would be met with beatings.

Allen had also initially expressed interest in Ron and Dan's breakaway group, but Brenda was vocal regarding her dislike of polygamy and openly shared her concerns about the authoritarian measures that the Lafferty brothers were championing.

Ron and Dan's wives, Dianna and Matilda, also sought advice from Brenda about their husbands' troubling behaviour. Dianna eventually walked away from her marriage with Ron and moved to Floria, taking their six children with her, which he subsequently blamed Brenda for.

Ron also believed that Erica "would grow up to be just as despicable as her mother", according to court documents.

The pair headed to Nevada from Salt Lake City after killing their family members, where they were arrested a month later at the Circus Circus casino in Reno.

Ron was found guilty of both counts of murder in 1985 and was sentenced to death, but his conviction was overturned in 1991 due to legal errors regarding his mental capacity.

He was once again charged with the killings but he was found to be mentally unfit to stand trial in 1992. He spent a period in a Utah State Hospital before he was deemed fit to stand following a hearing in 1994.

He was convicted of the killings in 1996 and sentenced to death.

Ron opted to be killed by firing squad rather than lethal injection, but following a change in Utah law, that would only be permitted if lethal injection drugs were not available.

He died at the Utah State Prison of natural causes in 2019. He was 78.

Dan, who is now in his mid 70s, is serving a life sentence at Utah State Prison. He claimed to have killed both Brenda and Erica, but one of the brother's acquaintances said that Ron had admitted to killing Brenda and had thanked Dan for murdering Erica.

According to Charles Carnes, Ron said: "I can't believe I killed her. Thank you, brother, for doing the baby because I don't think I had it in me."

Under the Banner of Heaven is available to stream in full in the UK on both ITVX and Disney Plus – sign up to Disney Plus for £7.99 a month or £79.90 a year now.

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