As an Idaho jury weighs whether doomsday author Chad Daybell should get the death penalty after being convicted in the murders of his first wife and his second wife's two children, family members of the three victims gave emotional statements to the court on Friday.
The jury found him guilty on all counts in what prosecutors said was a plot to pursue "money, power and sex."
Thursday's verdict in the capital murder trial comes more than a year after Daybell's second wife, Lori Vallow, was also convicted of murdering her two youngest children -- Joshua "JJ" Vallow, 7, and Tylee Ryan, 16. Their remains were found on a property in Idaho belonging to Daybell in June 2020 after the children had been missing for several months.
MORE: Doomsday author Chad Daybell found guilty in triple-murder caseDaybell, 55, was charged with murder and conspiracy in the deaths of the two children as well as his former wife of nearly 30 years, Tamara "Tammy" Daybell, 49, with whom he had five children. She died in their home on Oct. 19, 2019, with the cause of death asphyxiation, prosecutors revealed during Vallow's trial. Daybell and Vallow were married in Hawaii two weeks later.
Prosecutors said Daybell, the author of books about the apocalypse, promoted spiritual beliefs to justify the murders and had claimed that all three were possessed and "marked" them for death so that he and Vallow could be together "unencumbered by earthly relatives, earthly obstacles."
Daybell was also found guilty of two counts of insurance fraud related to $430,000 in life insurance policies he had on Tamara Daybell for which he was the beneficiary, prosecutors said.
During victim impact statements delivered ahead of the jury deliberations on the sentencing, several family members recalled their grief over Tamara Daybell's sudden death on Oct. 19, 2019, and the ensuing anguish and anger to learn that, following an exhumation to conduct an autopsy, she was murdered.
"My sister should not be dead right now," Samantha Gwilliam told the court. "She should be here alive, smiling, with her family and friends. She should be doting on her grandchildren and taking care of her animals."
"It is a cruel world that has taken her from us. We need to feel some peace for the first time in five years," she continued. "I miss my sister every day. I will grieve for her for the rest of my life. I speak up for her now because she needs a voice."
Their brother, Matthew Douglas, said Tamara Daybell was the "emotional heart and glue of our siblings' group."
"I still can't wrap my head and heart around the chain of events," he said, saying this has been a "nightmare that you feel never ends."
MORE: Lori Vallow Daybell sentencing updates: 'Doomsday' mom gets life in prison without paroleBen Douglas said the pain of losing their sister was "immeasurable" and has been compounded by also impacting their relationship with her children -- a sentiment echoed by his family.
"The tragedy of the case has harmed our family's relationship with the kids," her father, Ron Douglas, told the court. "I will remain open to rebuilding a relationship with them. It makes me angry, and it destroys me to know Tammy was treated how she was."
The eldest sibling, Michael Douglas, told the court that he did not sleep for six weeks after learning the results of the autopsy, and that his peace has been "stolen."
"I now have an angry part that has become, hopefully, not a permanent part of me," he said.
Her siblings expressed their shock and horror at learning that two children were also killed.
"I retched and sobbed over learning about JJ and Tylee," Gwilliam said through tears.
Ryan was a child from Vallow's third marriage while JJ was the nephew of her fourth husband, Charles Vallow, whom they adopted.
Kay Woodcock, JJ's grandmother, described her "immense pain" over the boy's death, which she called a "betrayal that can't be explained."
"There's a hole in my heart, in the hearts of every member of my family, that can never be filled and will remain for the rest of my life," she said, crying.
She said JJ was incredibly smart and compassionate and cried over the fact that she could not create more memories with him.
"The constant question remains -- who would he have become?" she said. "Would he be a famous scientist with incredible math skills? What would his amazing imagination have bloomed into? Would have been the next Albert Einstein, Steve Jobs, Tim Burton, Elon Musk? We will never know. But we do know how incredibly special he was to us."
Ryan's aunt, Annie Cushing, said she and her niece bonded over their love of pop culture and she had planned to bring the teen to New York City for her 18th birthday.
"Tylee had her whole life ahead of her. She had dignity, she had dreams, she had goals," Cushing said. "The defendant stole that."
The children's brother, Colby Ryan -- Vallow's eldest child -- expressed his grief at not seeing his siblings grow up.
"It's very hard for me to put into words what it means to have lost my entire family," he told the court. "In short, I've lost everything I've ever known."
He said his three children will never know Ryan's kind heart or JJ's "silly, goofy personality."
"But more importantly, Tylee and JJ lost their lives," he continued.
MORE: Chad Daybell's pursuit for 'sex, money and power' led to 3 murders, prosecutor claims in opening statementThe jury began deliberations Friday afternoon in the sentencing on whether the circumstances of the case warrant the death penalty, being sought by the state for what they called the "heinous" manner of the deaths.
"The defendant exhibited utter disregard for human life. Tylee was only 16 years old. JJ was only seven years old. Tammy -- a 49-year-old mother of five, the mother of the defendant's kids," prosecutor Lindsey Blake told the jurors Friday prior to the sentencing deliberations. "It didn't matter the age of the victim or who relied on them and loved them. If they were in the way of Chad and his plan and/or if there was money to be gained for Lori and Chad, those individuals were marked for death."
Defense attorney John Prior meanwhile painted Daybell as a quiet, small-town man committed to faith and family before blaming Vallow as a "bomb" dropped in his life, causing chaos.
"She was the trajectory that changed the plan," he told the court Friday. "You don't go back on 29 years of marriage with nothing as far as a speeding ticket, raising five wonderful children."
Daybell did not address the court during the sentencing phase of the trial. He also did not take the stand to testify in his own defense prior to the verdict.
Vallow was sentenced to life in prison without parole in July 2023 for the murders of her two children and for conspiring to kill them and Tamara Daybell. The judge had granted the defense's motion to dismiss the death penalty in her case.
She also faces charges over the death of her fourth husband, Charles Vallow, who was shot and killed by her brother in 2019.
Since the death penalty was established in Idaho in 1864, the state has carried out 29 executions, most recently in 2012, according to the Death Penalty Information Center.
There are currently eight residents on death row in Idaho, according to the state Department of Corrections.
ABC News' Jeffrey Cook contributed to this report.