BOISE, Idaho (AP) — The adult children of an Idaho man accused of killing their mother and his girlfriend’s two young kids testified in his defense this week, saying their mother’s health was declining before she died.

The testimony from Chad Daybell ‘s children on Monday marked the start of his legal defense in a complicated triple murder trial that began last month. Daybell’s daughter, Emma Murray, told jurors that her father was deeply distraught after her mother died, and that Murray — not Daybell — was the person who objected to an autopsy being performed.

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 Joshua “JJ” Vallow and 16-year-old Tylee Ryan. Last year, their mother, Lori Vallow Daybell, received a life sentence without parole for the killings.

Chad Daybell and Lori Vallow Daybell married just two weeks after Tammy Daybell’s death, raising suspicion among local law enforcement officials. Tammy Daybell’s body was later exhumed, and officials say an autopsy showed she died of asphyxiation. But Daybell had told officials that Tammy Daybell had been sick, and that she died in her sleep.

“I know the grief he felt was real,” Murray said, describing Daybell’s demeanor the morning after her mother died. “He may not have had the same romantic relationship with my mother that he had in the past, but I knew he valued her as a person and seeing her die was very traumatic.”

Over the past seven weeks, prosecutors have called dozens of witnesses to bolster their claims that Chad Daybell and Lori Vallow Daybell conspired to kill the two children and Tammy Daybell because they wanted to get rid of any obstacles to their relationship and to obtain money from survivor benefits and life insurance. Prosecutors say the couple justified the killings by creating a detailed and apocalyptic-focused belief system involving claims that people could be possessed by evil spirits and turned into “zombies,” and that the only way to save a possessed person’s soul was for the possessed body to die.

The case 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 Alex Cox 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 that she died of asphyxiation. Vallow Daybell and Chad Daybell married just two weeks after Tammy Daybell died, surprising family members.

Nearly a year after they went missing, the children’s remains were found buried on Chad Daybell’s property in eastern Idaho. Investigators later determined both children died in September 2019. Prosecutors say Cox conspired with Chad Daybell and Vallow Daybell in all three deaths, but Cox died of natural causes during the investigation and was never charged.

Friends of Tammy Daybell described her as being energetic and fit, regularly taking exercise classes and training to run in a 5K. But Daybell’s son Garth Daybell told jurors Monday that his mother’s health had been declining in the months before she died, and that he was worried because she was getting tired easily and would sometimes faint.

Murray made similar statements, saying that her mother was anemic, bruised easily and that she didn’t like sharing her health concerns with others. She also said that Tammy Daybell increased her life insurance policy on her own, without consulting Chad Daybell. Prosecutors then showed Murray the life insurance form, which included Chad Daybell’s signature.

Defense attorney John Prior also asked Chad Daybell’s children about other aspects of the prosecution’s case. Murray said she was the person who searched online for details about the wind direction in the area the day that Tylee Ryan died. Law enforcement officials have said Ryan’s remains were burned before they were buried in Daybell’s yard.

Garth Daybell told jurors that he lived with Chad and Tammy Daybell, and he heard no disturbances the night his mother died even though he was up until the early morning hours and had a bedroom next to his parents. He said he later felt like police officers and prosecutors were trying to pressure him to change his story during the investigation into his dad, even threatening him with charges at one point.

“They were telling me my story was untrue and I needed to change it,” Garth Daybell said.