PHOENIX >> An Idaho man accused along with his wife of conspiring to commit murder in the killings of her two children will not face criminal charges in Arizona in the earlier shooting death of his wife’s former husband.

Prosecutors in metro Phoenix declined to file a charge against Chad Daybell in the July 2019 killing of Charles Vallow, saying there was no reasonable likelihood of winning a conviction. Daybell’s wife, Lori Vallow Daybell, was charged late last month with conspiring to commit murder in Vallow’s death.

She is already at the center of a complicated criminal case in Idaho, where prosecutors allege she conspired with Chad Daybell to kill her son 7-year-old Joshua “JJ” Vallow, daughter 17-year-old Tylee Ryan and Daybell’s late wife, Tammy Daybell. Lori and Chad Daybell hold apocalyptic religious beliefs that prosecutors claim they used to justify the killings.

Police say they didn’t find any obvious communications between Lori and Chad Daybell that showed Chad Daybell was involved in the planning of Vallow’s killing.

John Prior, attorney for Chad Daybell, declined to comment on the decision not to prosecute his client in Arizona.

Police say Vallow was fatally shot nearly two years ago by Lori Daybell’s brother, Alexander Lamar Cox, when Vallow went to pick up his son at his estranged wife’s home in Chandler, Arizona.

Cox told police he killed Vallow in self-defense and wasn’t arrested. He died five months later from what medical examiners said was a pulmonary blood clot.

Cox’s account of the shooting has since been called into question by investigators.

They say Cox waited about 43 minutes to call 911 after shooting Vallow — and records show during this time that Cox called his sister Lori.

Investigators say Daybell acted as if he performed life-saving measures on Vallow, when it didn’t appear he had performed emergency aid.

And Cox claimed he shot Vallow twice while Vallow was standing, but forensic evidence shows Vallow was already on the floor when the second shot was fired, police said.

Lori Daybell, her daughter Tylee and Cox claimed Vallow started a physical dispute that led Daybell to leave the home with both her children. Tylee and Lori reported hearing a gunshot as they were leaving, police said.

Police say Daybell took Vallow’s rental car and cellphone. GPS data showed she went to get fast food for her son and got flip flops at a pharmacy before returning home.

Nearly two weeks before he was killed, police say Vallow found a fictitious letter that his estranged wife had sent to someone. The discovery triggered plans by Vallow to stage an intervention on her behalf.

The letter, written as if it came from Vallow, asked Chad Daybell to come to Arizona to assist him with writing a book.

Vallow accused his estranged wife of writing the letter as an excuse for Chad to visit her and demanded she come clean about her relationship with Chad Daybell — or he would tell Daybell’s wife about it, police said.

The intervention was to occur the day before Vallow was killed, but Lori found out about the plan and warned three other people about it, including Cox.

The day before Vallow was killed, police say Lori asked someone to cancel her plans to attend a wedding in Utah, saying that “We both need to stay her to defend ourselves” and “It’s coming to a head !”

Four months before his death, Vallow filed for divorce from his wife, alleging that she had become infatuated with near-death experiences and claimed to have lived numerous lives on other planets before her current life.

He also alleged she had threatened to financially ruin and kill him, according to court records, which noted that Vallow sought an order of protection and a voluntary evaluation of his wife at a mental health facility.

The Idaho case against Lori Daybell is on hold while she undergoes treatment at a mental health facility. A judge had her committed last month after determining she wasn’t competent to assist in her defense. Chad Daybell has pleaded not guilty to the charges.

After Vallow’s death, Lori Daybell and the children moved to Idaho, where Chad Daybell lived. He ran a small publishing company with his wife, Tammy Daybell, and released several of his own books — doomsday-focused fiction loosely based on the theology of The Church of Jesus Christ of Latter-day Saints.

Tammy Daybell died in October 2019, and her obituary said she died in her sleep of natural causes. But authorities grew suspicious when Chad Daybell married Lori Daybell just two weeks later.

Police began searching for Tylee and JJ after relatives raised concerns. Police say the Daybells lied to investigators about the children’s whereabouts before quietly leaving Idaho.

Months later, they were found in Hawaii without the children, whose bodies were eventually found buried on Chad Daybell’s Idaho property.