(CNN) -- The Utah Supreme Court has reversed Warren Steed Jeffs' two convictions on charges of rape as an accomplice and ordered a new trial, saying that instructions given to jurors were erroneous.

Jeffs, the "prophet" of the Fundamentalist Church of Jesus Christ of Latter-day Saints, or FLDS, was sentenced to two consecutive terms of five years to life after he was convicted in September 2007. He was accused of using his religious influence over his followers to coerce a 14-year-old girl into marrying her 19-year-old cousin.

"We regret the effect our opinion today may have on the victim of the underlying crime, to whom we do not wish to cause additional pain," the court said. "However, we must ensure that the laws are applied evenly and appropriately, in this case as in every case."

In Jeffs' trial, Elissa Wall testified that she repeatedly told him at the time that she did not want to be married and was uncomfortable with sexual advances from her husband, Allen Steed. She said Jeffs advised her to pray and submit to her husband, learn to love him and bear his children, or risk losing her "eternal salvation."

Wall was 21 at the time of Jeffs' conviction in 2007. Her attorneys made her name public at the end of the trial, with her consent. She is married to someone else and has left the FLDS.

The first count of rape as an accomplice against Jeffs was alleged to have occurred shortly after Wall and Steed were married, when the two first had sex, the Utah Supreme Court opinion said. The second was alleged to have occurred after Jeffs refused to "release" Wall from her marriage and told her to "give herself to [Steed] ... mind, body and soul."

Prosecutors relied on three separate portions of the law defining the circumstances under which sex is non-consensual, the opinion said. Under those portions, the victim must express a lack of consent through words or conduct, the victim must be younger than 18 years, and "the actor" must be in a position of special trust in relation to the victim.

"Jeffs argues that the instruction erroneously focused the jury on Jeffs' actions and position of special trust, rather than on Steed's, for the purpose of determining whether Wall consented," the opinion said.

The justices agreed, saying the jurors should have been asked to consider whether Steed was in a position of special trust and whether Steed lured or induced Wall into having sex.

"The state interprets the term 'actor' to mean the 'defendant,' " the opinion said. "We conclude that the state's interpretation is erroneous."

"We're thrilled," said Jeffs' defense attorney, Wally Bugden. "We're overjoyed. We're ecstatic that the Supreme Court agreed with us. ... The state just had the wrong legal theory."

Jeffs is "an unpopular religious figure in our state," Bugden said, and the media have "had a field day portraying him as an evil, horrible, pernicious individual." The court, he said, was able to put that aside and base its decision on the evidence and legal theories, not on emotion, and determine that the erroneous instructions led jurors to "an erroneous result."

The defense has always maintained that marrying someone, encouraging them to make their marriage work and "be fruitful and multiply ... that is not the same thing as saying to a husband, 'I'm encouraging you to rape your wife,' " Bugden said.

He said he had not had a chance to speak to Jeffs but planned to do so Tuesday afternoon.

Assistant Utah Attorney General Laura Dupaix told CNN affiliate KSTU that the opinion is "going to make it difficult, I think, for us to do future prosecutions in cases where some of these men in positions of power -- almost complete power, like Warren Jeffs is -- to prosecute them for forcing young girls into these marriages. I think that's really the part of this opinion that is most disappointing for us."

The justices sent the case back to the lower court for a new trial.

The state has 14 days to request a rehearing with the Utah Supreme Court, said Nancy Volmer, spokeswoman for Utah state courts. The justices would then grant or deny that petition. If a request is not made, the case will be sent back to the trial court within 30 days, and the lower District Court then has 30 days to schedule a hearing.

Jeffs is being held at the Utah State Prison in Draper, about 30 miles south of Salt Lake City. The issue of whether he should be released pending a new trial would be addressed at the District Court hearing, Volmer said.

However, Bugden said, Jeffs will be transferred back to Washington County in southern Utah, where he was convicted -- and closer to the FLDS community. "We will be asking for bail," he said.

But Jeffs has a federal indictment against him for unlawful flight to avoid prosecution, said Melodie Rydalch, a spokeswoman for the U.S. Attorneys' Office in Utah. The indictment states Jeffs traveled across state lines in 2006 to avoid prosecution.

"There are federal detainers in place with the Utah State Prison and Washington County," Rydalch said. "Although his attorney is saying he will ask for a bail hearing in the Utah state court, our federal detainers are in place."

Rydalch added if Jeffs is not held on state charges, authorities will bring him into federal custody.

Bugden said he expects Washington County prosecutors to decide quickly whether they want to proceed with the case.

Jeffs had been awaiting trial in Arizona on four charges of being an accomplice to sexual conduct with a minor. But last month, a judge dismissed those charges. Matt Smith, the Mohave County, Arizona, prosecutor, had asked the court to throw out the charges, citing "much more serious charges" against Jeffs in Texas and the desire of his alleged victims that he "face these more serious charges as soon as possible."

Jeffs was indicted in Texas in 2008 on a felony charge of sexual assault of a child. An indictment accuses Jeffs of assaulting a child "younger than 17 years of age and not legally married to the defendant" in January 2005. If convicted on the Texas charges, Jeffs could face a maximum penalty of five to 99 years or life in prison and a fine of $10,000.

The FLDS drew national attention when Jeffs was arrested during a routine traffic stop in August 2006. At the time, he was on the FBI's Ten Most Wanted list.

The sect is a 10,000-member offshoot of the mainstream Mormon church. Its members openly practice polygamy at the Yearning for Zion Ranch in Eldorado, Texas, and in two towns straddling the Utah-Arizona state line: Hildale, Utah, and Colorado City, Arizona. Critics of the sect say young girls are forced into "spiritual" marriages with older men and are sexually abused. Sect members have denied that any sexual abuse takes place.

Jeffs had led the sect since his father's death in 2002.