The Utah Supreme Court rejected a former Hildale police officer's bid to decriminalize polygamy Tuesday, in a historic split decision that wrestles with same-sex unions and the meaning of marriage.

Four of the court's five justices said Rodney Holm's relationship with a 16-year-old ''spiritual wife'' fell ''squarely within the realm of behavior criminalized by our state's bigamy statute.'' The majority added that constitutional protections for religion don't shield polygamists from prosecution.

But in a 37-page dissent, Chief Justice Christine M. Durham said she would have overturned Holm's bigamy conviction, finding the law doesn't apply to relationships that lack a marriage license.

Durham pointed to the increasing number of couples who live together outside the bonds of a traditional marriage, and noted they are not prosecuted.