A U.S. District Court judge ruled to effectively decriminalize polygamy in Utah Friday – a win for a GW Law School professor who was the lead attorney in the case.

Jonathan Turley, a professor of public interest law, had argued that Utah’s ban on multiple-person marriages was unconstitutional. He filed the case in July 2011 on behalf of the Brown family, best known for their reality TV show “Sister Wives.”

“Plural families present the same privacy and due process concerns faced by gay and lesbian community over criminalization,” Turley wrote on his blog Friday. “With this decision, families like the Browns can now be both plural and legal in the state of Utah.”

The family said the laws violated their right to privacy. The Browns are members of the Apostolic United Brethren Church, a fundamentalist branch of the Mormon Church.

Judge Clark Waddoups said the portion of the law forbidding “cohabitation” was a violation of the First Amendment. Multiple marriage licenses would still be illegal.

Utah officials began investigating the Brown family after their show aired in 2010.

Watch the original trailer for the show below: