Opening statements began Wednesday in the trial of Chad Daybell, who is charged in Idaho with killing his wife and the two youngest children of his then-girlfriend, Lori Vallow Daybell, in an unusual case rooted in extremist religious beliefs. The trial comes nearly a year after Vallow Daybell was convicted of murdering her children.

Prosecutor Rob Wood told jurors Wednesday morning that Daybell became obsessed with Vallow Daybell after they met at a religious conference in 2018. Wood said the pair had an affair and came to see Daybell’s wife at the time, Tammy Daybell, and Vallow’s children, Joshua “JJ” Vallow and Tylee Ryan, as obstacles to their future who were sometimes called dark spirits or zombies.

“When he had a chance at what he considered his rightful destiny, he made sure that no person, no law would stand in his way,” Wood said about Daybell. “His desire for sex, money and power led him to pursue those ambitions and this pursuit led to the deaths of his wife and Lori’s two innocent children.”

The pair was initially set to be tried together, but a judge severed their trials after Daybell waived his right to a speedy trial.

Daybell, 55, is facing charges of first degree murder, insurance fraud, and conspiracy to commit murder and grand theft in connection with the deaths of Tammy Daybell, 7-year-old “JJ” and 16-year-old Tylee. Vallow Daybell received a life sentence without parole for the killings.

Prosecutors say the couple justified the three killings with doomsday beliefs, part of an elaborate scheme to eliminate any obstacles to their relationship and to obtain money from survivor benefits and life insurance. Vallow Daybell referred to her two youngest kids as zombies, one friend testified during her trial.

Who is Chad Daybell?

Chad Daybell was a member of the Church of Jesus Christ of Latter-day Saints and self-published fiction loosely based on its teachings.

In 2019, he tried to fraudulently collect on his late wife’s life insurance policy, and Vallow Daybell continued to collect both children’s Social Security benefits after they died.

Chad Daybell has pleaded not guilty to the charges, and the trial is expected to take more than two months. Prosecutors said they will seek the death penalty if Daybell is convicted.

The grim story began in the fall of 2019, when extended family members reported the two children missing and law enforcement officials launched a search that spanned several states. The subsequent investigation took several unexpected turns.

Vallow Daybell and Chad Daybell were having an affair when both of their spouses died unexpectedly, investigators said. Vallow Daybell’s husband was shot to death by her brother in Arizona in July 2019; the brother told police it was in self-defense.

Several months later, in October 2019, Tammy Daybell died. Chad Daybell initially told police she was battling an illness and died in her sleep, but an autopsy later determined she died of asphyxiation. Vallow Daybell and Chad Daybell married just two weeks after Tammy Daybell died, surprising family members and drawing suspicion from authorities.

Friends later told detectives that Vallow Daybell and Chad Daybell believed they had been reincarnated and were tasked with gathering people before a biblical apocalypse.