NEW YORK (AP) — The founder of a religious order that treats Roman Catholic priests who molest children concluded in the 1950s that offenders were unlikely to change and should not be returned to ministry, according to his letters, which were obtained by plaintiffs' lawyers.

The Rev. Gerald Fitzgerald, founder of the Servants of the Paraclete, was so sure of the priests' inability to control themselves that he tried to buy an island to isolate them.

Fitzgerald discussed the issue with Pope Paul VI and in correspondence with several bishops, according to the National Catholic Reporter, an independent newspaper that reported the full content of the letters Monday.

The documents challenge recent statements by U.S. bishops that before the clergy sex abuse scandal erupted in the 1980s and again in 2002, they were unaware of the risks of moving predators among parishes.

Fitzgerald wrote in a 1952 letter to Bishop Robert Dwyer of Reno, Nevada that "real conversions will be found to be extremely rare."

"Hence, leaving them on duty or wandering from diocese to diocese is contributing to scandal or at least to the approximate danger of scandal," he wrote.

The Los Angeles law firm Kiesel, Boucher & Larson, which has brought many abuse cases against California dioceses, persuaded a judge in New Mexico to unseal the letters in 2007, according to Helen Zukin, an attorney at the firm.

The attorneys then verified that the documents were authentic during depositions with Fitzgerald's successor as the Paracletes servant general, the Rev. Joseph McNamara, Zukin said.

Leaders of the Servants of the Paraclete could not be reached for comment Monday.

Fitzgerald set up the Paraclete treatment center in the late 1940s in Jemez Springs, New Mexico, mainly to help clergy struggling with alcoholism and emotional troubles. Soon, bishops began sending him priests who had molested young people or could not keep their celibacy vows.

In a 1957 letter to Bishop Matthew Brady of Manchester, New Hampshire, Fitzgerald wrote that abusive priests only pretended to repent and change "to be again in a position where they can continue their wonted activity." He said eventually the church would have to establish "a uniform code of discipline and of penalties" to protect the priesthood.

More than four decades later, the U.S. Conference of Catholic Bishops did just that. It created a national discipline and child protection policy after news reports and court files unsealed in 2002 showed that many bishops had moved guilty priests from assignment to assignment without notifying parents or police.

Under the new plan, offenders are barred from church work or ousted from the priesthood altogether. American dioceses have paid more than $2.6 billion in abuse-related costs since 1950, according studies commissioned by the U.S. bishops.

By the 1960s, Fitzgerald was losing control over the direction of the religious order, and medical and psychological professionals began working at the center — a change he had resisted. Those experts said some abusers could return to ministry.

The New Mexico treatment center closed in the 1990s in the face of lawsuits over priests who had molested children while staying at the Jemez Springs site or after being treated there.