The leaders of a fundamentalist Mormon offshoot called Knights of the Crystal Blade took each other’s daughters as child brides, according to a search warrant that was recently unsealed.

The men, Samuel Shaffer and John Coltharp, were arrested in December and charged with kidnapping after an Amber Alert was issued for Coltharp’s daughters.

Iron County Sheriff’s Office Detective Nathan Houchen detailed an interview with Shaffer in a search warrant affidavit submitted Dec. 11. Shaffer told police that he married Coltharp’s 8-year-old daughter, and that Coltharp married his 7-year-old daughter.

On Monday, Coltharp was charged in Sanpete County with sodomy of a child for a sexual assault that occurred on Aug. 1, according to charging documents. Shaffer, who is being prosecuted in Iron County, has not been charged with additional crimes.

This undated photo provided by the Iron County Sheriff's office shows Samuel Shaffer. Police say Utah men Shaffer and John Coltharp are under arrest a after search near a remote, makeshift compound turned up two girls taken by their father, Coltharp, to join an upstart sect relatives say is based around polygamy and doomsday. Iron County Sheriff's Lt. Del Schlosser said Tuesday, Dec. 5, 2017, the girls aged 4 and 8 were found cold but uninjured after deputies combed the desert near the makeshift compound made of storage containers on Monday. (Iron County Sheriff's Office via AP)

The Sheriff’s Office began investigating Coltharp and Shaffer on Dec. 1, when Coltharp’s ex-wife alerted the office that Coltharp had fled with their four children after losing custody of them in the couple’s divorce.

Spring City police found Coltharp at his home and arrested him on suspicion of custodial interference, but his children were in the care of Shaffer. Coltharp is being held in the Sanpete County jail.

On Dec. 4, police raided a compound about a mile west of Lund, where the men’s Knights of the Crystal blade group had set up shipping containers to form a makeshift residence. Police found Coltharp’s parents, also believed to be members of the group, and his two sons, the affidavit states.

Coltharp’s parents told police that Shaffer had spent the past few nights sleeping in a tent with the four girls and had left with them the night before.

An Amber Alert was issued for Coltharp’s daughters. The four girls were recovered Dec. 5 after Shaffer was found walking a few miles from the compound that night. Two girls were recovered from a “deplorable” single-wide trailer, the affidavit says, and the other two were found in an empty 50-gallon water drum, where they had been housed for 24 hours in subfreezing temperatures.

The girls were taken to an area hospital, and one was flown to Primary Children’s Hospital.

Shaffer was arrested and charged with two first-degree-felony counts of kidnapping and four second-degree-felony counts of child abuse. Coltharp was charged with first-degree-felony kidnapping and obstruction of justice, a class A misdemeanor.

The men have preliminary hearings Wednesday — Shaffer in Iron County and Coltharp in Sanpete County. Coltharp had an initial hearing on the sodomy charge Wednesday.

According to the affidavit, Spring City Police Chief Clarke Christensen was contacted by an out-of-state man who said he communicated with Shaffer and Coltharp through social media regarding Knights of the Crystal Blade.