ST. ANTHONY — Chad and Lori Vallow Daybell are being investigated for conspiracy, attempted murder and/or murder by the Idaho Attorney General’s Office, according to a letter obtained Friday by EastIdahoNews.com.

The letter from Deputy Attorney General Colleen Zahn is in response to Fremont County Prosecuting Attorney Marcia Murdoch’s April 7 request that the AG assist in the investigation of Tammy Daybell’s death.

Tammy, who was married to Chad, died suddenly on Oct. 19 at her Salem home. Investigators have called the death suspicious, and her body was exhumed from the Springville Evergreen Cemetery in Utah in December. Detectives are still awaiting autopsy and toxicology reports, Fremont County Sheriff Len Humphries tells EastIdahoNews.com.

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Chad and Tammy Daybell | Facebook

Zahn writes the attorney general’s office will provide prosecutorial assistance without local prosecutor involvement, and the attorney general will take charge of the case.

“All decisions regarding the case shall be the responsibility of the AG,” the letter states.

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Fremont County will pay for all costs associated with the case other than the salaries of AG personnel involved. The letter was written and signed by Zahn and accepted and signed by Murdoch on Thursday, April 9.

Humphries and a spokesman for the attorney general’s office had no comment on the letter. Murdoch did not respond to EastIdahoNews.com.

READ: Letter from attorney general about Fremont County Daybell case

The investigation does not necessarily mean charges will be forthcoming.

Chad has not been arrested or charged with any crimes. He married Lori in Hawaii within weeks of Tammy’s death.

In a separate case, Lori is being held in the Madison County Jail on two counts of felony child abandonment regarding her missing children, 7-year-old Joshua “JJ” Vallow and 17-year-old Tylee Ryan. They have not been seen since September, and Lori and Chad refuse to tell law enforcement where they are.

Sean Bartholick, Chad’s attorney, had no comment on the attorney general’s letter, and Mark Means, Lori’s attorney, has not responded to EastIdahoNews.com.