Houston - A Texas appeals court ruled Thursday that state authorities and a lower court judge abused their authority by illegally seizing up to 468 children from their homes at a polygamist ranch in West Texas last month.
The rebuke threw the largest custody case in American history into turmoil, with some lawyers saying the children could soon be reunited with their families. Many of the mothers have been criss-crossing Texas visiting their children in foster homes.
According to the court, the state did not establish proper grounds to remove the children from their families, who belong to the Fundamentalist Church of Jesus Christ of Latter-day Saints, or F.L.D.S. The F.L.D.S. broke off from the mainstream Mormon church after it had disavowed polygamy in 1890.
The agency raided the Yearning for Zion ranch on April 3 after someone had called an abuse hot line and said that she was a 16-year-old child bride being abused by her older husband in the church's compound. The caller has still not been found.
Officials of the state Department of Family and Protective Services on Thursday defended their actions as having been taken in the children's interest and said they were considering their next steps.
The unanimous ruling by three judges of the Third Court of Appeals in Austin revoked the state's custody over a large group of the children and by extension almost certainly the rest, for what it called a lack of evidence that they were in immediate danger of sexual or physical abuse.
The appeals court said the record "does not reflect any reasonable effort on the part of the department to ascertain if some measure short of removal and/or separation would have eliminated the risk." It also said the evidence of danger to the children "was legally and factually insufficient" to justify their removal and it said the lower court "abused its discretion" in failing to return seized children to their families.
The ruling - an unusual mandamus opinion granting relief in a case not yet decided - came on the application of 38 women who challenged state custody and another 54 who filed a second action. But lawyers said the burden was on the state to show why it should not apply to the rest of the children as well.
State agency officials, who have been criticized for their handling of the raid, said taking all the children in the church's compound were necessary because the culture of the sect led to illegal under-age marriage for girls and acceptance of that practice by boys, a pattern that the state said endangers both sexes.
The children and their mothers, who refused to be separated from them, were initially housed in a former military facility and an entertainment arena in San Angelo. Last month, after two days of often chaotic hearings, a judge in San Angelo ordered that all of the children be placed in Texas foster care facilities.
The court action on Thursday followed a writ of mandamus filed by the Texas Rio Grande Legal Aid group - the largest provider of legal aid in the state - and some mothers from the sect who were representing their children.
"We're extremely happy with the ruling," Cynthia Martinez, a spokeswoman for the Texas Rio Grande Legal Aid group, told The Houston Chronicle.
"The way that the courts have ignored the legal rights of these mothers is ridiculous," Julie Balovich, also of Rio Grande, added. "It was about time a court stood up and said that what has been happening to these families is wrong."
The state made its case in an earlier court hearing. "There is a culture of young girls being pregnant by old men," said Angie Voss, an investigator with Child Protective Services, who participated in the raid and interviewed girls at the ranch. Ms. Voss testified that she had found evidence that "more than 20 girls, some of whom are now adults, have conceived or given birth under the age of 16 or 17."
The F.L.D.S. leader, Warren S. Jeffs, was convicted last year on a rape charge for imposing marriage between an under-age girl and older man in Utah.
Contributing reporting were Dan Frosch in Denver, Gretel C. Kovach in Dallas, Anahad O'Connor in New York and John Dougherty in Las Vegas.