In the letter, Mr. Cruz wrote that Bishop Barros, who was a priest at the time, witnessed the abuse.
Pope Francis has repeatedly discounted the accusations against Bishop Barros as slander, and his defense of him cast a shadow over a trip he made to Chile in January. Last week, facing mounting criticism for siding with clergy members over victims, the pope sent the Vatican’s top sex crimes investigator to Chile to hear their accusations.
The disclosure of the letter has raised difficult questions for the pope.
Did he read the letter and decide not to tell reporters about it? Did he choose to believe Bishop Barros over Mr. Cruz? Or did he never read the letter, or perhaps read it but forget about it?
For Mr. Cruz, the pope has become “just like the others.”
“He covers up and doesn’t listen to the victims,” he said.
Some veteran Vatican analysts said that perhaps the pope had information not available to other people.
Marco Politi, a Vatican expert and the author of the book “Pope Francis Among the Wolves,” said the pope’s continued belief in the innocence of Bishop Barros must have been based on an internal investigation. If the pope erred, Mr. Politi said, “it was that he did not send Bishop Charles Scicluna earlier.” Bishop Scicluna is the investigator the pope sent to Chile.
The case against Bishop Barros erupted in 2015 when the pope named him, a former chaplain in the Chilean armed forces, to lead the Osorno diocese amid widespread protest. Bishop Barros has denied knowing about the abuse until 2010, when accounts emerged in the news media.
Concerned by the accusations against the Chilean bishop, members of the Commission for the Protection of Minors traveled to Rome so that they could deliver Mr. Cruz’s letter to the pope.
“We all felt that the Barros appointment had been a mistake, and when Juan Carlos told me he had been trying to be heard, we thought that this was an opportunity to get the details directly to the pope,” said Marie Collins, a survivor of abuse who resigned from the commission last year in frustration over its inaction. “If Barros hadn’t recognized abuse when it had happened under his eyes, it was difficult to see how those in his diocese would be properly protected,” she said.
In April 2015, four members of the commission met with Cardinal Sean O’Malley, who led the commission, in the Casa Santa Marta, where the pope lives. Ms. Collins asked him to personally deliver the letter to Francis.
They commemorated the moment when they delivered Mr. Cruz’s letter with a photograph. “We thought it would be nice for the survivors of abuse to know that we were doing the best that we could do for them,” Ms. Collins said.
The working group issued a statement at the time saying that it was essential for a bishop to enact effective policies and monitor compliance, “in the light that sexual abuse is so common,” but did not mention Mr. Cruz’s letter.
At the commission’s next meeting several weeks later, Cardinal O’Malley confirmed that he had delivered the letter to the pope, Ms. Collins said. Mr. Cruz said Cardinal O’Malley had told him that he delivered the letter himself.
Last month, after the pope’s remarks dismissing allegations against Bishop Barros as “slander,” Cardinal O’Malley issued a remarkable defense of the victims.
Delivering the letter was the only time, as far as Ms. Collins knows, that members of the commission tried to speak to the pope about a specific case, she said. But she also said that while she is convinced that the letter was given to the pope, she cannot be sure if he read it.
“I have no idea because he has continued to support Barros over three years, and never met with the survivors,” she said. “I can’t judge. The pope is a good man. I have no idea why he wouldn’t have considered the concerns of the members of his commission.”
The new commission for the protection of minors — whose members have not been announced — is expected to hold its first plenary session in April.
Mr. Saunders, who was dismissed from the commission in 2016 for being too outspoken, was also present at the April 2015 meeting. The commission members had hoped to speak directly with the pope, but instead met with Cardinal O’Malley, he recalled.
“O’Malley said the letter would be handed to Francis, who I think was literally in the next room,” he said.