The suit alleges LDS leaders knew Tilson had sexually abused children in wards where he lived, but never reported the abuse to authorities or warned other church members. Facing similar allegations in past lawsuits, the LDS Church has settled several cases, including a $3 million settlement in a Portland, Ore., lawsuit.
A church spokesman said the church "strongly disputes" the suit's allegations and is "gratified that the Court of Appeals decided the church cannot be held responsible as an institution when an individual member commits private criminal conduct."
The church also says it "unequivocally condemns child abuse in any form, and our hearts go out to victims of abuse and their families."
Salt Lake City attorney Mary Corporon, who represented the mother and son, did not return a phone call. The plaintiffs were identified only as Jane and John Doe.
Tilson, 62, has been excommunciated.
The lawsuit claimed the church covered for Tilson, allowing him to remain a "high priest" and Boy Scout leader with access to children.
Writing for the appeals court Thursday, Judge Pamela T. Greenwood said the church had no duty to warn the mother and son because it had no "special relationship
them, and the alleged abuse did not occur while the victims were at church events.
"Tilson was not a [church] employee, agent, or clergy member," the opinion said. "Although [the church] conferred upon Tilson the positions of high priest and Scout leader, the sexual abuse suffered by plaintiffs occurred in Tilson's house and was unrelated to [the church] or any of its activities."
The justices declined to consider another key issue raised by the case: whether such lawsuits can be brought against organizations, rather than individual leaders.
Utah state law says child sexual abuse victims can bring a civil lawsuit "only against a living person who intentionally perpetrated the sexual abuse or negligently permitted the sexual abuse to occur."
That question could be decided in a separate case now pending before the Utah Supreme Court. Third District Judge Dennis Frederick cited the statute in dismissing a lawsuit brought by a couple who claim they were not told about their foster child's history of sexually assaulting other children.
They sued the Utah Youth Village and the state of Utah after the boy abused their 3-year-old son.
Since the mid-1980s, the LDS church has educated its all-male lay clergy about sexual abuse and has created a system that flags the records of members accused of child abuse. The church also has set up a toll-free number for leaders to report abuse.
At churches of all faiths, efforts to protect members go beyond teaching about right and wrong to background checks for employees and training for reporting of abuse.
Stephen Hutchinson, legal advisor for the Episcopal Diocese of Utah, said his church does background checks of employees and those who volunteer to work with children and has training about appropriate behaviors.
''There is a practical, as well as legal, limit of what churches can do about off-premises behavior of their members, as much as you try to teach what's proper,'' he said.
The diocese's Rev. Dan Webster said church members try to look out for each other. He cited an example of a former parishioner who opened her home to a new member and was warned to check his references.
''A Christian community that is open and welcoming is ripe for a person who is looking for victims,'' Webster said. ''We have to be very careful.''
Tribune reporter Pamela Manson contributed to this report.
* A Utah woman and her son sued convicted child molester George K. Tilson and the LDS Church in 2003.
* The suit claimed church leaders had reports between 1966 and 2003 that Tilson had sexually abused at least 10 children, yet failed to tell police or warn other members.
* Tilson allegedly abused the mother in 1976, when she was a teenager, and her son at about age 5, between 1993 and 1996.
* The suit claims both were pressured by church leaders not to publicly expose Tilson and to seek counseling only from therapists who supported forgiveness for him.
* In 1996, Tilson pleaded guilty to attempted sexual abuse of a child for the assault of an 11-year-old girl in his hot tub. He was sentenced to probation and six months in jail.