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Crime News Cults

Who Are The Lafferty Brothers And Why Did They Kill A Mormon Mom And Her Baby?

Ron and Dan Lafferty were cult members who murdered Brenda Lafferty and her infant daughter, believing God told them to "remove" the mom and child from Earth.

By Gina Tron
Ron Lafferty is escorted out of the Utah County Court House

The homicidal brothers at the heart of “Under the Banner of Heaven” are based on two real siblings who committed a terrible crime. 

The FX mini-series, which hits Hulu on Thursday, is based on Jon Krakauer’s 2003 true crime bestseller “Under the Banner of Heaven,” which details the 1984 murder of Mormon mother Brenda Lafferty and her infant daughter, Erica. 

She was murdered by her brothers-in-law, Ron and Dan Lafferty, who forced their way into the home of their brother, Allen Lafferty; he was Brenda’s husband.

The siblings allegedly blamed Brenda for helping Ron’s wife leave him. They were also angry that Brenda didn't want Allen to join their polygamous cult, School of the Prophets, which they formed in 1984 after leaving the Fundamentalist Church of Jesus Christ of Latter-Day Saints.

Ron’s extreme religious views had led to his ex-communication from the FLDS Church and his divorce in 1984, the Salt Lake Tribune reported last year. But he blamed the divorce on Brenda and two of Brenda’s friends. He believed that God also wanted him to “remove” those two friends after he killed Brenda and her baby, according to court records. 

Ron and Dan Lafferty strangled Brenda “with a vacuum cord, and slit her throat with a knife,” according to court records. They also slashed Erica’s throat, nearly decapitating the child, Deseret News reported in 2019. The murders occurred on July 24, the same day that commemorates the Latter-day Saint pioneers’ arrival in the Salt Lake Valley. Ron claimed the revelation told him to “remove” them to keep them from “obstructing God’s work.” 

When Ron Lafferty was convicted of murder in 1985, he blamed the decision on a conspiracy between the state, the LDS Church, and “unseen spiritual forces” including the dead father of the judge from his trial, according to the Salt Lake Tribune.

Before his conviction, four court-appointed mental health examiners determined that “Lafferty was unable to determine the boundaries between himself and spiritual beings, that he was experiencing ‘blurred ego boundaries,’ that he was suffering from a ‘religious martyr complex,’ that his mind had created a ‘paranoid pseudo-community involving the legal and social systems,’” according to court records. 

The brothers were supposed to go on trial together but Ron tried to hang himself to death in jail in December of 1984. He also attempted to kill Dan, according to the Deseret News. As a result, they both had separate trials and both were convicted of murder in 1985. Ron was sentenced to death and Dan got life after one juror spared him.

The case remains one of Utah’s most infamous crimes, KUTV reported earlier this year.

At 78, Ron died of natural causes at the Utah State Prison in 2019, the Deseret News reported at the time. Dan is still alive and serving a life sentence. 

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