(NewsNation) — Until November 2019, the names of Lori Vallow and her husband Chad Daybell weren’t widely known.

That all changed two days before Thanksgiving, when Lori Vallow’s two children, Joshua “JJ” Vallow and soon-to-be 17-year-old Tylee Ryan, went missing in Idaho. Tylee and JJ’s remains were later found on Chad Daybell’s property.

Now, Lori Vallow is on trial. Jury selection started Monday at the Ada County Courthouse in Boise, Idaho.

The unhinged family dynamic started two years earlier when Lori Vallow, a devout member of the Church of Jesus Christ of Latter-Day Saints — and once described as a patient, wonderful mother — started reading and studying books by author Chad Daybell.

These books were about preparing for the end of the world. Cult experts say Daybell, who followed a group called “Preparing a People,” took the organization’s teachings to another extreme. He would talk about “zombies” and souls leaving bodies.

“What Chad Daybell taught his followers was that there were negative or evil spirits that could occupy a human body and that the only release that person would have was when they died,” cult expert Rick Ross told NewsNation.

When Lori Vallow first started getting sucked into these ideas, she was married to businessman Charles Vallow. Their life looked like storybook perfection, as they raised Tylee and JJ in Arizona.

But then Lori and Chad Daybell began doing religious podcasts together, and their relationship grew. That’s when Vallow’s family says she began to change.

Charles Vallow, Lori’s fourth husband, went to the police after he said his wife threatened to murder him. He soon filed for divorce. Six months later, Charles Vallow was shot to death by Lori’s brother, Alex Cox. Cox claimed it was self-defense. Cox would also ultimately die from what were described as natural causes.

With Charles Vallow dead, Lori moved her family to Rexburg, Idaho to be closer to Chad.

“He was bringing those people to Rexburg, and that was the cult,” Ross said.

FILE – In this aerial photo, investigators search for human remains at Chad Daybell’s residence in Salem, Idaho, on June 9, 2020. A mother charged with murder in the deaths of her two children is set to stand trial in Idaho. The proceedings against Lori Vallow Daybell, the wife of Chad Daybell, beginning Monday, April 3, 2023, could reveal new details in the strange, doomsday-focused case. (John Roark/The Idaho Post-Register via AP, File)

Just days after moving to Idaho, Tylee disappeared in September 2019 — after a friend said Lori Vallow described her daughter as a “zombie.” Two weeks after that, JJ also vanished.

“It was a heck of a sequence of events, and it certainly seemed to be circling around this doomsday group of people,” private investigator Rich Robertson said.

Then, Chad Daybell’s wife Tammy mysteriously died a month later.

Amid all of this, Lori Vallow and Chad Daybell flew to Hawaii to get married. Missing from the wedding photos are JJ and Tylee.

JJ’s grandparents grew concerned and called the police for a welfare check in November.

Authorities searched Chad Daybell’s Idaho property and found the bodies of Tylee and JJ buried in shallow graves. Tammy Daybell’s body was exhumed, and her death was ruled suspicious.

Lori Vallow and Chad Daybell were eventually indicted on two counts of conspiracy to commit first-degree murder and grand theft by deception for the death of Tylee and JJ. The couple was also indicted on the charge of conspiracy to commit murder in the death of Tammy Daybell.

While Chad Daybell is also indicted on one count of first-degree murder in Tammy’s death, his and Lori Vallow’s trials will be separate. Both have pleaded not guilty.

Now, Lori Vallow is on trial. She faces up to life in prison if convicted. Jury selection, which began Monday, could take up to eight weeks.

The Associated Press contributed to this report.