SALT LAKE CITY >> A federal judge ruled Friday that key parts of Utah’s polygamy laws are unconstitutional, handing a legal victory to a polygamist family that stars in the TV reality show "Sister Wives."

U.S. District Court Judge Clark Waddoups said in the ruling that the phrase in Utah law that forbids cohabitation with another person was a violation of the First Amendment.

Washington D.C.-based attorney Jonathan Turley has said that Kody Brown and his four wives drew the attention of Utah authorities because of their TLC hit series. The Brown family filed their lawsuit in July 2011, and fled Utah for Las Vegas last year under the threat of prosecution.

Turley argued the case before Waddoups in January.

Utah’s bigamy law is stricter than the laws in 49 other states — most of the other states prohibit people from having multiple marriage licenses. Utah makes it illegal to even purport to be married to multiple partners or live together.

The Salt Lake Tribune reports Waddoups took a narrow interpretation of the words "marry" and "purports to marry" in his ruling. That means that bigamy remains illegal in Utah only in the literal sense, such as when someone fraudulently acquires more than one marriage license.

"The decision affects a far greater range of such relationships than the form of polygamy practiced by the Browns," Turley said in a statement Friday. "It is a victory not for polygamy but privacy in America."

Utah officials had sought to have the suit thrown out. They first argued that the Browns couldn’t challenge the bigamy law because they hadn’t been charged. State attorneys later argued for dismissal because a prosecutor had pledged not to prosecute them for bigamy.

But Waddoups wrote in a 2012 ruling that the promise from the Utah County Attorney’s Office appeared to be a ploy to avoid the suit.

Kody Brown said in a statement Friday that the family was "humbled and grateful" for the ruling.

"While we know that many people do not approve of plural families, it is our family and based on our beliefs," he said. "Just as we respect the personal and religious choices of other families, we hope that in time all of our neighbors and fellow citizens will come to respect our own choices."