The American Civil Liberties Union of Utah has filed a brief on behalf of a polygamist couple seeking to adopt six children, stating that polygamy should not be the sole factor in determining fitness of parents.

In December, a 5th Circuit Court judge denied a petition by polygamists Vaughn and Sharane Fischer to adopt the six children of a woman who died two months after becoming Fischer's third wife.Fifth District Judge Dean Conder ruled that the Hildale, Washington County, couple could not adopt the six children because "polygamy is a crime and the practice of polygamy constitutes immoral conduct."

In a press conference Tuesday, Michele Parish-Pixler, ACLU acting director, said her organization is challenging the constitutionality of the law outlawing polygamy.

She argued that the original Supreme Court ruling of 1878, which outlawed the practice of polygamy, resulted in "relentless persecution of Mormon families. Unfortunately, there was not the ACLU at that time to stand up against this religious persecution." The Church of Jesus Christ of Latter-day Saints banned the practice of polygamy Oct. 6, 1890.

The 19th century high court decision has no relevance to today's society, Parish-Pixler said.

Thousands of polygamists live openly in Utah. The state is required to show that polygamous conduct poses a substantial threat to public safety, peace or order. "Presumably, if polygamy poses such a threat, Utah law enforcement would be vigorously prosecuting polygamists," she said.

Taking no position on the qualification of the Fischers as parents or the quality of their home environment, the ACLU urges Utah's high court to consider the Fischer's polygamous practice as just one of many factors regarding the children's best interests.

The Fischer case involves the six children, ages 5 to 19, of Brenda Johanson Thornton, who died of cancer Aug. 17, 1987. Thornton had signed over custody of the children to the Fischers before her death and had requested they legally adopt her children.

But the adoption petition was opposed by Pat and Janet Johanson, Thornton's two non-polygamist sisters. They maintained the children should not be raised in an environment that has been deemed illegal by the courts.

The Fischers' appeal is scheduled to be heard by the Utah Supreme Court in June.