Prosecutors claimed that Chad Daybell's pursuit of "sex, money and power" led to him killing his first wife and his second wife's two children during opening statements Wednesday in his triple murder trial in Idaho.
His capital murder trial comes nearly a year after his second wife, Lori Vallow, was convicted of murdering her two youngest children -- Joshua "J.J." Vallow, 7, and Tylee Ryan, 16 -- in the so-called doomsday plot.
Prosecutors claim that Vallow and Daybell thought the two children were "dark spirits" and "zombies" and murdered them in 2019, approximately a year after meeting at a religious conference. The children's remains were found on an Idaho property belonging to Daybell in June 2020 following a monthslong search, police said.
Ryan's DNA was found on two tools in Daybell's shed, prosecutor Rob Wood said during his opening statement in Daybell's trial on Wednesday.
Daybell was also charged with murder in the death of his former wife, Tamara Daybell, who died Oct. 19, 2019, of asphyxiation, prosecutors previously revealed during Vallow's trial. Seventeen days later, Vallow and Daybell married in Hawaii, prosecutors said.
During his opening statement on Wednesday in the Boise courtroom, Wood described Daybell as a "seemingly ordinary man" who was the author of books about the apocalypse and possessed a "desire for sex, money and power" -- echoing the prosecutor's statements during Vallow's trial.
"When he had a chance to what he considered his rightful destiny, he made sure that no person, no law would stand in his way," Wood told jurors. "This 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 children."
Wood told jurors they can expect to hear during the trial Daybell's "extended text messages to reveal his mindset and his motivations."
MORE: Murder trial of Chad Daybell, husband of 'doomsday' mom Lori Vallow, set to beginDefense attorney John Prior told the jurors during his opening statement Wednesday that Daybell had "no remarkable background" and was married to his first wife for nearly 30 years and had five children with her before meeting Vallow.
He described Vallow as a "beautiful, vivacious person" who was "very manipulative" and pursued Daybell, her fifth husband.
He told jurors they can expect to hear about Vallow's past tumultuous relationships and the death of her fourth husband, Charles Vallow, who was fatally shot by her brother in 2019 during a confrontation at her Arizona home. Police were investigating claims that her brother, Alex Cox, shot his brother-in-law in self-defense when Cox died from natural causes months after the fatal shooting.
Prior told jurors that Cox "would do anything" for his sister.
"Whenever there was a problem or threat, you will hear testimony that Alex Cox came to the rescue," Prior said.
Prior told jurors they will hear testimony from a DNA expert who determined that fingerprints found on the plastic that JJ was discovered in belonged to Cox.
Prior also said a forensic pathologist will testify that there was no way to determine Tamara Daybell's cause of death. Several of Daybell's five children also plan to testify about their mother's health, Prior said.
Jury selection for Daybell's trial, which began on April 1, took six days. The trial is expected to last around nine weeks, court records show.
Daybell, 55, was also charged with conspiracy to commit murder in the death of his former wife and two counts of insurance fraud related to life insurance policies he had on her for which he was the beneficiary, prosecutors said.
MORE: Lori Vallow Daybell found guilty in murder of her 2 childrenHe pleaded not guilty to his charges. He faces the death sentence if convicted of murder.
His case is being presided over by the same judge from Vallow's trial, Judge Steve Boyce.
Boyce sentenced Vallow to life in prison without parole after the jury in her trial found her guilty of all charges. The judge had granted the defense's motion to dismiss the death penalty in her case before her trial began.
Vallow has also been accused of conspiring to kill her fourth husband, Charles Vallow. She was indicted on one count of first-degree murder by a Maricopa County grand jury in 2021 in connection with his fatal shooting.
She was also charged with first-degree premeditated murder for allegedly plotting to kill the ex-husband of her niece.
She pleaded not guilty to both charges last year.