VATICAN CITY (RNS) The Vatican police corps celebrated their yearly festival on Friday (Oct. 5), the feast day of their patron, St. Michael the Archangel. But after the scandals of recent months, it was a more subdued celebration than normal.

The Vatican police force, or Gendarmeria, has found itself in an uneasy spotlight during the trial of Pope Benedict XVI's former butler.

It was Vatican policemen who conducted the investigation on the butler, Paolo Gabriele, and arrested him on May 23, after a search of his apartment inside Vatican City revealed an enormous trove of papers, including hundreds of confidential papal documents.

But it was Vatican policemen, too, who allegedly held Gabriele in a cell so small that he couldn't “even stretch his arms,” where the light was kept on for 24 hours a day and where he said he endured “psychological pressure.”

The Gendarmeria issued a swift rebuke of Gabriele's allegations and threatened a countersuit if a Vatican investigation reveals his claims to be unfounded.

The alleged abuse inside the Vatican jail is just one of the details of the activities of the Vatican police corps that have come to light during the trial.

During the proceedings, Gabriele's lawyer, Cristiana Arru, more than once seemed to suggest that the police investigation methods had been flawed. At Arru's request, the court rejected from evidence two interrogations of Gabriele conducted by the Gendarmeria's commander, Domenico Giani, without the presence of a lawyer.

Vatican policemen also admitted to not using gloves during the search of Gabriele's apartment, and couldn't describe where a nugget, presumably made of gold, had been found within his house.

The missteps don't seem sufficient to weaken the case against Gabriele, who on more than one occasion admitted to photocopying the pope's confidential letters.

"The Gendarmeria seems to have built a strong case against the butler,” says Maurizio Bellacosa, an expert on Vatican law at LUISS University in Rome.

But they might cast a shadow on a corps that in recent years has prided itself on its growing professionalism as a full-fledged police force with international recognition. In 2008, the Gendarmeria joined Interpol, an international organization that brings together police forces from 190 countries.

Under the leadership of Giani, a former member of the Italian secret service, Vatican policemen have received professional training by the FBI and widened the scope of their activities – sometimes irking the pope's traditional protectors, the colorfully clad Swiss Guards.

Founded only in 1971, the Gendarmeria now has a high-tech “control room.” It has also recently created a “quick response” unit to respond to “high-risk situations” and an “anti-sabotage” unit.

“They have invested heavily on technology to protect the pope's security and confidentiality,” says Italian security expert Gianni Cipriani. “After all, a lot of people come and go within the Vatican.”

In fact, critics say that sometimes the Gendarmeria have overstepped appropriate boundaries, including searching the butler's house in Castel Gandolfo, a small village south of Rome where the pope's summer residence is located.

It is unclear from trial proceedings whether the house falls under Vatican or Italian jurisdiction; if it's Italian territory, it could add to earlier charges that the Gendarmeria improperly pursued investigations outside the small territory of the Vatican City State.

A similar episode, with two Vatican policemen tailing a man in Italian territory, is reported in Gianluigi Nuzzi's best-selling book “Sua Santita,” or “His Holiness,” which compiles most of the secret papers leaked by Gabriele. One of the chapters is devoted to the rising prominence of the Gendarmeria in the world's smallest state.

Gabriele himself admitted to a “morbid” curiosity about Vatican policemen during the investigation, adding that he had been “shocked” by the “unfair treatment” given to the corps chaplain, who had been unceremoniously sacked after five years.

According to his statements during the trial, Gabriele started sharing confidences with two men who were “knowledgeable” about the Gendarmeria, and then reported his findings to the pope's personal secretary, Monsignor Georg Gaenswein.