VATICAN CITY — Pope Benedict XVI’s former butler, Paolo Gabriele, went on trial Saturday on charges of stealing the pope’s confidential papers and leaking them to the press, an unprecedented security breach that set off an embarrassingly public airing of backroom intrigue and allegations of corruption at an institution known for its secrecy.
Gabriele appeared tired but serene throughout the two-hour hearing, which was held in a sparsely furnished courtroom in a palazzo behind the apse of St. Peter’s Basilica.
The Vatican tribunal, consisting of three judges, upheld motions to strike some of the evidence gathered against Gabriele and to split off the trial of a codefendant, a Vatican computer expert charged with aiding and abetting.
A spokesman for the Vatican, the Rev. Federico Lombardi, said the atmosphere in the courtroom was ‘‘serene.’’ Television cameras and recording equipment were not admitted, and a pool of eight reporters allowed inside briefed other journalists after the hearing.
Gabriele, who has admitted taking the documents, faces up to four years in prison if he is convicted of aggravated theft. He is scheduled to take the stand when the hearing continues Tuesday.
Gabriele told the judge examining the case that he saw ‘‘evil and corruption everywhere in the church,’’ and believed that he had to expose it because the pope ‘‘was not correctly informed’’ about what was going on, according to court records.
Public exposure, he told investigators, ‘‘could be a healthy thing to bring the church back on the right track.’’
The trial of Gabriele, 46, caps a turbulent moment for the Roman Catholic Church, racked by a pedophilia scandal involving some of its clergymen, interfaith and intrafaith disputes, and challenges to preserve its moral authority within rapidly changing societies. Some of the leaked documents opened an especially unflattering vista onto some questionable administrative practices as well as inner wrangling at the Vatican.
The hunt for the source of the leaks led to Gabriele, a father of three who had worked in the Vatican for 20 years and was discovered to have stashed what prosecutors described as a ‘‘vast quantity’’ of confidential documents in his Vatican City apartment.
He passed some to an Italian journalist, Gianluigi Nuzzi, who published them in May in ‘‘His Holiness: The Secret Papers of Pope Benedict XVI.’’
The butler was arrested May 25 and later released to house arrest. An investigation into the charges led to a formal indictment in August.
After his arrest, Gabriele wrote a letter to the pope asking for forgiveness, according to Carlo Fusco, one of his lawyers. Fusco later left the defense team because of differences over strategy..
The pope appointed a commission of three cardinals to investigate separately, and they reported their findings — which remain confidential — to the pope this summer.
This is the highest-profile court case in years to take place in a tribunal that has follows the procedures of a 19th-century Italian penal code and handles only a few dozen, mostly insignificant, cases a year.
If convicted and sentenced to prison, Gabriele will serve the time in an Italian prison, because the Vatican does not have one. But it is widely believed that the pope will grant a pardon.