Texas authorities are fighting a challenge to a pair of search warrants served during the raid on the Fundamentalist LDS Church's YFZ Ranch.

In a 51-page court filing, the Texas Attorney General's Office lays out a case for "probable cause" that a crime had occurred on the Utah-based polygamous church's sprawling Eldorado property.

"Both affidavits set forth facts establishing probable cause on each element of sexual assault of a child (both warrants) and bigamy (second warrant) and properly allege a particular description of the property to be served," deputy Texas attorney General Stephen R. Lupton wrote.

Lawyers for the FLDS Church, YFZ Ranch leader Merril Jessop and Lyle Jeffs are challenging the constitutionality of the search warrants. A hearing has been scheduled Oct. 1 in San Angelo, Texas, on the issue.

Arguing why the search warrants were valid, Texas authorities said they based it on phone calls to a crisis shelter hotline by a 16-year-old girl named "Sarah," who said she was pregnant, being abused and could not leave the YFZ Ranch.

"Such a description of the premises to be searched for the rescue of a claimed victim and for evidence of a crime — a gated ranch and the structures and vehicles located on it — passes constitutional muster," Lupton wrote.

Beyond that, Lupton said Texas Rangers had probable cause to believe ranch residents could be hiding her, or preventing her from leaving.

"The second affidavit included facts above and beyond the first affidavit and was based on observations made by law enforcement and government officials during the execution of the first search warrant," Lupton wrote. "Such observations established probable cause to believe that victims, suspects, and evidence of crimes of sexual assault and bigamy could be located in temples, temple annexes, places of worship, vaults, safes, lockboxes and locked drawers."

Lupton laid out a long list of young women who were questioned by either Texas Rangers or Child Protective Services caseworkers. One spoke of a 16-year-old girl who was married, had a baby and was currently pregnant. When asked how old she was, one looked at a man who responded: "You are 18," an answer the girl parroted.

The call itself is believed to be a hoax, something the FLDS Church's attorneys point out in their challenge. A Colorado woman has been declared a "person of interest" in the ongoing investigation. Dale Barlow, a convicted sex offender from Colorado City, Ariz., whom "Sarah" named as her husband, was dropped from an arrest warrant as it became apparent the call was a fake.