The Vatican says that because Mr. Wesolowski was a member of its diplomatic corps and a citizen of the Holy See, the case would be handled in Rome. But even many faithful Catholics in this nation, home to the oldest Catholic cathedral in the Americas, say they are unsettled that a Vatican official could have been using children for sex, yet was not arrested and tried in their own country.

“From the pure standpoint of justice, he should be tried in the country where the acts took place because the conditions for trying him will not be the same elsewhere,” said Antonio Medina Calcaño, dean of the faculty of law and political science of the Autonomous University of Santo Domingo. “But all we can do is hope that the courts in the Vatican will treat this with the severity that it really deserves.”

The Vatican spokesman, the Rev. Federico Lombardi, did not say when the Wesolowski trial will start, who is representing the former nuncio, or whether he is at liberty while he awaits trial. Under Vatican law, sexual abuse charges can bring a maximum of 12 years in prison and a fine of nearly $200,000.

A Dominican bishop, Victor Masalles, visiting Rome in late June, said in a Twitter message that he was surprised to see Mr. Wesolowski “strolling the Via della Scrofa,” in the city’s picturesque ancient center. He added, “The silence of the Church has hurt the people of God.”

A Man Known as ‘The Italian’

The waterfront promenade in the Dominican capital is dominated by a 50-foot monument to the 16th-century Spanish friar Antonio de Montesinos, dressed in robes and preaching the fiery sermon that made him famous: denouncing the slavery and abuse of the indigenous people by their Spanish colonists.

It was at the heel of this colossus, on the deserted upper plaza in the shadow of the friar’s robes, Mr. Aquino said, that he was often molested by the man he knew as “the Italian.” The man always chose a bench that would allow him to see the rare visitor coming up the staircase, and would watch the boy masturbate, would touch him or would touch himself, said Mr. Aquino, now 17. Other times, they went to the rocky beach below the statue.

Mr. Aquino, whose family is originally from Haiti, left school in the eighth grade, earning $1.50 on a typical weekday by shining shoes. But he said that the man gave him more than $10 the first time they met, in 2010, to shine his shoes and to swim naked in the ocean while Mr. Wesolowski watched.