"Admittedly, [the investigation] was brought on by the publicity surrounding the show," Paul said. "It's rare because most of the time people don't bring this kind of attention onto themselves. But it is a state law, and we're going to investigate it."
Paul would not say whether police have found evidence that Brown legally married more than one of his four wives: Meri, Janelle, Christine and Robyn Brown. But, he noted, Utah code defines bigamy through cohabitation, not just through legal marriage contracts.
Detectives are still investigating and have not turned the case over to prosecutors to be screened for charges, Paul said. Bigamy is a third-degree felony.
The law puts police in a position where they have no choice but to investigate "upstanding families" who aren't breaking any other laws, said Anne Wilde, cofounder of Principle Voices, a plural marriage advocacy group.
"This just shows all the more reason the crime needs to be reduced ... so that this doesn't happen to consenting adults," she said. "We have a right to form our families in the way we select, just like all the other alternative-lifestyle families in the U.S. which, by the way, are more than 50 percent of all families."
Kody Brown has 13 children and three stepchildren. He and his wives have said their plural marriage is no secret; they have told their employers and coworkers and their children's friends and teachers, they said in interviews this weekend with The Tribune.
"I know the family so well, and they're such fantastic people," Wilde said. "They're not flaunting it at all. They're trying to educate people that this is a viable lifestyle."
Brown did not return calls Monday night from The Tribune. A TLC spokeswoman said the network was unaware of the investigation before being called by a Tribune reporter and had no further comment.
Tribune reporter Vince Horiuchi contributed to this report.
Utah's bigamy statute
A person is guilty of bigamy when, knowing he has a husband or wife or knowing the other person has a husband or wife, the person purports to marry another person or cohabits with another person. ... It shall be a defense to bigamy that the accused reasonably believed he and the other person were legally eligible to remarry.
Utah Code: 76-7-101