The series is based on the real-life 1984 murders of Brenda Wright Lafferty and her 15-month-old daughter Erica Lafferty.
The town of Rockwell is fictional, and the real Lafferty case occurred in the town of American Fork, Utah.
In one scene, Josie says "The Jews, they need baptisms. . . . You know, if the Jews don't accept Christ, they . . . they're gonna find themselves in the Celestial Kingdom with Hitler." Jeb and Rebecca ask her to stop saying that kind of thing because it scares their daughters. Josie is referring to posthumous baptism-by-proxy, LDS doctrine that is now officially frowned upon. In 1994, it was revealed that the Church of Jesus Christ of Latter-Day Saints was regularly performing posthumous proxy baptisms of Jews, including Holocaust victims. The scandal, which echoed the forced conversions that Jews have faced throughout history, enraged Jews worldwide.
Series creator and adapter Dustin Lance Black was raised in the LDS Church. In a July 2022 interview with Kim Masters on KCRW's show "The Business," he said, "I saw my mother being abused [and] the church preferring she lean on church authority, as opposed to police authority, and that really didn't resolve things because it's the woman's place in Mormon home to create a home suitable to her priesthood holder, the father in the home. But the thing that's most disturbing about having witnessed that is how unremarkable it was. It was not just her. My mother was the president of the Relief Society in our area, which is the women's group in the church, and I was keenly aware that our story was not special." He also said that he was "very attached" to the church as a teen, despite the discomfort he felt with its intolerant policy on LGBTQ rights and his growing realization that he was gay. "I was devout. I didn't know any different. It's how the design of the church is. I was six days a week in church, which I enjoyed, whether that's Sunday school, or Boy Scouts. It was all Mormon, and it's all I knew. And it felt very safe. So leaving the church was not something I wanted to do, but I followed my mother out as a teenager." Black was also a staff writer on "Big Love," about a modern polygamous Mormon family.
This is the second religious/cult themed projects Rory Culkin has been in, the first being Waco (2018). He subsequently played a Charles Manson-like murderous cult leader in the Black Mirror episode "Beyond the Sea."