The Utah Supreme Court on Tuesday overturned the rape-as-an-accomplice conviction of Warren Jeffs, the prophet and leader of a polygamist sect based on the Arizona-Utah border, leaving his fate in the legal system uncertain.

In a unanimous decision, justices found that jurors in the case were given improper instructions by Washington County Judge James Shumate before reaching their verdict that Jeffs contributed to the 2001 sexual assault of teenage victim Elissa Wall, then 14, by directing her marriage to an adult cousin.

Jeffs, 54, once was listed among the FBI's most wanted fugitives, and faced criminal prosecutions related to child rapes in three states.

Because Mohave County prosecutors dismissed the Arizona charges against Jeffs in June, the Supreme Court decision in Utah could mean the leader of the Fundamentalist Church of Jesus Christ of Latter Day Saints faces only remaining criminal charges in Texas.

Brian Filter, senior deputy in the Washington County Attorney's Office, said no determination has been made on whether Jeffs will be retried.

"We've just gotten the opinion. It's lengthy and obviously very complicated," Filter said. "From the beginning, we've sought justice in this case, and that's what we'll continue to do."

The ruling stunned former FLDS church member Flora Jessop of Phoenix, who wept over the phone as she denounced the court's findings: "I think the Supreme Court of Utah just raped Elissa Wall, and I wonder who's going to prosecute that case," said Jessop, who was abused before she fled the sect at age 16. "Anybody with kids should move out of Utah and Arizona because there's not justice here. It's a betrayal of all of us � every child victim � It just sickens me."

By contrast, Jeffs' Utah attorney, Walter Bugden Jr., said it was "thrilling" to see justices uphold the rule of law by vindicating a man who has been vilified in Utah and nationwide.

Noting that the FLDS sect is an unsanctioned offshoot from the mainstream Mormon church, which renounced polygamy more than a century ago, Bugden said: "The Utah Supreme Court was willing to exonerate a religious figure who is very unpopular in this state. That's the truly exciting part � It's a significant decision because of Utah's religious roots."

Bugden said the criminal case in Utah was based on a flawed legal theory designed to convict Jeffs on charges that would result in the maximum punishment.

The Supreme Court found that Judge Shumate incorrectly advised jurors that they could find Jeffs guilty as an accomplice to rape based on the notion that his authority and marriage ceremony led to the sexual assault, regardless of whether that was his intention.

Bugden said he believes Utah will be forced to drop charges not only because new jury instructions will make a successful prosecution almost impossible, but because of evidence developed by defense lawyers in Arizona which has undermined Wall's credibility. "I think they'd have immeasurable problems," Bugden said.

Michael Piccarreta, Jeffs' Arizona lawyer, said charges in Mohave County were dismissed in part because the alleged victim had conspired with a midwife to create false medical records of a miscarriage. While the medical document itself was not a vital to conviction, Piccarreta said, "fabricated evidence" and Wall's testimony in the Utah court would damage her believability in future proceeding.

"The Utah case is now effectively dead," Piccarreta said. "There is no evidence that Mr. Jeffs intended anyone at any time to engage in the rape of anyone."

Wall, co-author of a book titled "Stolen Innocence," could not be reached for comment. Her attorney was unavailable.

Gary Engel, a Mohave County investigator who has worked on the FLDS issues for several years, disputed Piccarreta's allegation against Wall, saying, "She didn't fabricate anything."

The FLDS church, once estimated to have 10,000 members, holds that plural marriage is ordained by God and essential to achieving the highest level of salvation. Church members claim that polygamy, including the assignment of child brides, are acts of religious freedom protected by the U.S. Constitution.

Nearly a decade ago, attorneys general in Arizona and Utah began investigating child marriages in Colorado City-Hildale, twin communities on the two states' border, as well as allegations of financial fraud, the banishing of young males and other issues.

At least a half-dozen sect members have been convicted of felonies related to sexual conduct with minors. Church-operated schools were shut down. Most of the property in Colorado City-Hildale, controlled by an FLDS trust, was turned over to a court-appointed trustee. A number of Colorado City police officers were stripped of law enforcement certification.

The arrest and conviction of Jeffs was viewed as the culminating event in that campaign. Now, Piccarreta and Bugden said, it appears Texas is the only remaining venue where Jeffs could be convicted, and charges there also are problematic.

The 2008 investigation in Eldorado, Texas, was launched after a deranged woman made a series of fraudulent phone calls to authorities, claiming to be a pregnant teenage abuse victim imprisoned within the FLDS Yearning for Zion Ranch.

In arguing to preclude evidence from the ranch in Jeffs' Mohave County case, Piccarreta said Texas authorities knew or should have known that the phone call was bogus. Instead of debunking the woman's distress calls, he said, Texas Rangers obtained a search warrant and raided the FLDS community with "legions of officers, helicopters and a tank."

More than 400 people were rounded up, with children temporarily removed from their parents. Jeffs was charged with having sex with an underage bride, but Piccarreta said the case hinges on evidence gathered during the questionable raid.

"The search is one of the top 10 in U.S. history in terms of being unconstitutional and illegal," he said. "Unless they can use the fruits of their illegal search, they cannot successfully prosecute Mr. Jeffs. I think this is a real test for the judicial system in Texas."

Jeffs, now incarcerated in Utah, was serving two sentences of five years to life.

An extradition hearing scheduled Tuesday was cancelled after the Utah conviction was overturned.

Carolyn Jessop, a former sect member who testified for Texas prosecutors in six convictions of FLDS men for sexual abuse of children, described the Utah ruling as "terribly discouraging."

Jessop, who authored "Triumph: Life after the Cult," a book about her escape from the FLDS sect, said she is confident Jeffs will be found guilty in Texas, even if there is no retrial in Utah.

In the meantime, she said, the Utah decision will empower FLDS leaders in their resolve to continue arranging marriages with underage children.

"I don't think they have any intention of stopping," she said. "They strongly believe that God is on their side."