Hulu’s Under the Banner of Heaven tells the true story of the 1984 Lafferty murders, with Andrew Garfield’s detective slowly uncovering who killed Brenda Lafferty and Mormonism’s role in her death. While actor Andrew Garfield’s Detective Pyre is a fictional character, Brenda Lafferty and the gross brutality done unto her were entirely real, with Under the Banner of Heaven trying to explain how the 24-year-old Mormon woman and her infant child were so cruelly slain. When Under the Banner of Heaven finally reveals who killed Brenda Lafferty, the true story will seem all the more haunting and disturbing.

Under the Banner of Heaven is an adaptation of the 2003 true crime novel of the same name by Jon Krakauer. The book has taken many of its findings from interviews and statements of the real-life Lafferty brothers. Along with detailing Brenda Lafferty’s upbringing, the Lafferty family’s devout Mormonism, and the family’s growing issues with the church, the book inspiration for FX on Hulu's original series featured much background on the formation of Mormonism and the LDS church. Just as religious zealotry and illusions of grandeur played a significant role in Brenda Lafferty’s murder, Under the Banner of Heaven’s author continually makes reference to several other examples of violent events and tendencies affiliated with the history of Mormonism.

Related: New Hulu Plans Could Help Save Alien & Predator Franchises

When Brenda Lafferty and her 15-month-old daughter, Erica, were found savagely killed in their home on Utah’s Pioneer Day in July 1984, their entire community, and the larger church, would be changed forever. Under the Banner of Heaven’s real-life crime involves much more than just Andrew Garfield’s detective beginning to question his faith, with Daisy Edgar-Jones’ (Noa in Hulu's Fresh) Brenda Lafferty and her relationship with her husband’s family diving deeper into the ideologies, cyclical patterns, and illusions of grandeur that led to her killers’ brutal actions. As Under the Banner of Heaven retells the horrific events of the crime, Andrew Garfield’s character will uncover the twist of who truly killed Brenda Lafferty and her daughter Erica.

Who Killed Brenda & Erica Lafferty In 1984

Under the Banner of Heaven Brenda & Erica Lafferty

On the evening of July 24, 1984, Brenda Lafferty was found by her husband with her throat slashed on the floor of her home after having been choked by the cord to a vacuum. In the nursery nearby, Brenda Lafferty’s 15-month-old daughter, Erica, was found in her crib with similarly horrifying and gruesome fatal wounds. It would soon be discovered that Brenda and her daughter were murdered by the elder brothers of her husband Allen – Ron and Dan Lafferty, played by Sam Worthington and the MCU's Wyatt Russell, respectively, in Under the Banner of Heaven. After being found in Nevada, Ron and Dan Lafferty were charged for the murders of their sister-in-law and infant niece, with the trials revealing that Ron killed Brenda while Dan murdered Erica. Under the Banner of Heaven’s real-life figures were found guilty, with the trial revealing how their disturbing extremism toward fundamentalist Mormonism influenced their crimes.

Why Ron & Dan Lafferty Killed Brenda & Erica Lafferty

Under the Banner of Heaven Dan & Ron Lafferty

Ron and Dan were two of the eight Lafferty siblings, with Brenda’s husband Allen being the youngest, coming from a notable Mormon family in Utah who was supposedly known for their strong family values. While this is how the family presented itself externally, the Laffertys’ real-life father from Hulu's true crime show frequently subjected the children to abuse and brutality, including an incident in which he beat the family’s dog to death with a bat. Such violence was instilled in the brothers at a young age, with various scriptures also contributing to the violent iconography of their devout religious upbringing. Under the Banner of Heaven’s book even revealed that Dan Lafferty claimed to have mimicked his killings after what was written in the scriptures.

Ron and Dan Lafferty decided to kill Brenda and Erica in 1984 after Ron claimed to have a divine revelation. Ron, who considered himself a prophet, and Dan had both been excommunicated from The Church of Jesus Christ of Latter-Day Saints for their extremist views, with the brothers joining the small sect of the School of the Prophets. This group subscribed to many of the beliefs of the original LDS church around the time it stopped polygamous practices in 1890, but the real-life crime story's cult didn’t necessarily associate themselves with the official fundamentalist Mormons. Upon the brothers’ movement into more extremist views, Ron’s wife divorced him after he wanted a polygamous marriage, with Ron blaming Brenda for his wife leaving him.

Related: Everything Murder Among The Mormons Leaves Out About Mark Hofmann

During this time, Dan and Ron’s polygamist cult led to the two growing their hair and beards long like old Mormon prophets, seeing themselves as church leaders and claiming to communicate with God. Under the Banner of Heaven’s real-life Brenda, who also grew up in a devout Mormon family in Idaho, openly disagreed with the Lafferty brothers’ fundamentalist views and the notion that Ron was a prophet, which made the brothers’ dislike for her grow. Ron then claimed that God sent him “removal revelations” about Brenda and her infant daughter Erica (who he believed would grow up to be like her mother), with the two explaining their killings as the will of God. Following Brenda Lafferty’s murder, the real counterpart for Sam Worthington's Under the Banner of Heaven role and Dan had planned to kill two more LDS church members in his “revelation,” but one wasn’t home, and they had missed the turn to the other’s location.

What Happened To The Lafferty Family After Brenda’s Murder

The Lafferty family in Under the Banner of Heaven.

After Dan and Ron Lafferty were arrested for Brenda’s murder in 1984, the brothers stood trial for their crimes, with both being found guilty. Dan Lafferty’s trial occurred in January 1985, with the murderer deciding to represent himself in court. Dan, who originally claimed that he committed both murders, was ultimately found guilty on two counts of first-degree murder and multiple other felonies, and he was sentenced to two life sentences in prison. Under the Banner of Heaven’s real-life Dan Lafferty is still alive today, serving his sentence in Utah’s State Prison. Before his own hearing in April 1985, Under the Banner of Heaven's Mormon Ron Lafferty attempted suicide in jail, with the incident leading to physical and mental damage that put him in Utah State Hospital. After several months, he was deemed competent to stand trial, where he was convicted and sentenced to death. Ron tried to appeal his case several times after 1985, with his competency found to be “restored” in 1996, where he was again tried, convicted, and given the death sentence. Ron then spent another 20 years on death row waiting to be executed, but died of natural causes in 2019.

As for the rest of the Lafferty family, Under the Banner of Heaven’s book doesn’t reveal much about what happened to them after Brenda’s murder and the brothers’ trial. Ahead of the Andrew Garfield-starring series, it appears that only one of the brothers still lives in Utah, with the others seemingly escaping to locations where the Lafferty name isn’t associated with such brutality. The Laffertys’ mother died in 2016 after living in Utah working at the Provo LDS Temple, with Allen rumored to have since remarried and relocated to Southern California, where he works on movie productions (via Deseret News).

More: Sony Has No Excuse Not To Give Andrew Garfield Another Spider-Man Movie Now