Chad Daybell, Lori Vallow's Husband Who's Charged with Murder, Should Get Death Penalty: Prosecutors

Chad Daybell is accused murdering Lori Vallow's two children and his first wife, Tammy Daybell

Chad Daybell. Photo: Rexburg Police Department

Prosecutors in Idaho are seeking the death penalty against Chad Daybell, the religious doomsday author accused of murdering his stepchildren and his ex-wife.

In May, Daybell and his wife Lori Vallow were indicted on charges of conspiracy to commit murder and first-degree murder in connection with the deaths of Vallow's two children, Joshua (J.J.) Vallow and Tylee Ryan.

Daybell was also charged with murder in the 2019 death of his first-wife, Tammy Daybell. He's also charged with two counts of insurance fraud related to life insurance policies he had on her.

Madison County Prosecuting Attorney Rob Wood and Fremont County Prosecuting Attorney Lindsey Blake filed their notice of intent to seek the death penalty Thursday.

"Our process in making this determination was lengthy and comprehensive," they wrote in a joint statement obtained by PEOPLE. "We conferred with those immediate family members of JJ Vallow, Tylee Ryan and Tammy Daybell, who have indicated a willingness to speak with us and allowed them an opportunity to provide their input if they wished to do so. The ultimate decision to seek capital punishment rests with the State, and after completing the entire process, we determined that the nature and magnitude of these crimes warrant the possibility of the highest possible punishment."

Lori Vallow. Dennis Fujimoto/AP/Shutterstock

In court documents, prosecutors said the murders were "especially heinous, atrocious, or cruel, manifesting exceptional depravity" and that Daybell "exhibited a propensity to commit murder, which will probably constitute a continuing threat to society."

The death penalty only applies to Daybell, who has pleaded not guilty to the charges against him. In May, Vallow was deemed mentally unfit to stand trial on the murder charges.

Joshua “J.J.” Vallow, at left, and his sister Tylee Ryan.

Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

"At this time, the defendant is not competent to proceed, and recommends restorative treatment," District Judge Steven Boyce wrote in his order, which placed a hold on the criminal proceedings against her.

J.J. was last seen on September 23, 2019, in Rexburg, Idaho, when his mother withdrew him from school, telling the principal she planned to homeschool him. Tylee was last seen at a Sept. 8 day trip to Yellowstone National Park. After they hadn't heard from the children in months, J.J.'s grandparents called authorities.

Chad Daybell, at left, with his deceased wife Tammy Daybell.

Vallow was arrested in Hawaii on February 20, 2020, after refusing the court order to turn over the children to police or child welfare officials.

She was charged with desertion and nonsupport of dependent children, resisting or obstructing officers, criminal solicitation to commit a crime, contempt of court and willful disobedience of court process or order. She previously pleaded not guilty to all of those charges.

Daybell was arrested on June 9, 2020, after the bodies of J.J. and Tylee were found on his property. After the discovery of the bodies, authorities charged the couple with murder.

Tammy Daybell died just two weeks before her ex-husband married Vallow — they were formally married just weeks before Vallow's children were declared missing.

Daybell told authorities that Tammy died in her sleep after going to bed with a cough. At the time she was otherwise believed to be in good health and had been training to run a race, reports EastIdahoNews.com.

Tammy's body was exhumed in December 2019, while the search for Vallow's children was still underway, reports EastIdahoNews.com. The 49-year-old was a mother of five.