Chad Daybell's son: "It was pretty plain that I needed to change my story"

The lawyer of Chad Daybell called on two people closest to him during the first day the defense could call witnesses to the stand in Daybell's triple-murder trial.

His adult kids, Emma Murray and Garth Daybell, said their mother's health was deteriorating before her sudden death.

Chad's daughter testified  that 49-year-old Tammy Daybell was not as healthy as several witnesses have described her.

"Her health started declining. I was really worried about it. She, well, she'd always be one to meet the demands of daily life without being exhausted and she started going to bed before dinner some nights," Murray said on the witness stand.

Tammy's cause of death was asphyxia and determined to be a homicide.

Prosecutors say Daybell claimed Tammy was possessed by a dark spirit. They say Daybell believed the children of his then-girlfriend Lori Vallow also possessed the dark spirit.

"Light means you're acting selflessly like the savior would be and dark would mean you're acting selfishly, focusing inward like Satan would be," Murray said.

"Lead prosecutor Lindsey Blake cross-examined the witness, asking her if her father told her the whereabouts of JJ Vallow and Tylee Ryan when they were missing for several months. She replied that Daybell said they were safe.

The two children were later found on Chad Daybell's property, buried in the backyard.

Daybell's son Garth said on the stand he felt threatened by the prosecution to change his testimony before charges came down.

"It was pretty plain that I needed to change my story to fit theirs," he said in response to a question from John Prior, the attorney for Daybell.

"And the event you didn't change your story, you'd be indicted by the grand jury?" Prior asked.

"Yes, and they had a list of charges that they were threatening me with," Garth said.

Daybell's son-in-law also took the witness stand.

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