In court today the pope's private secretary Georg Gaenswein said it was only when he read the book that he realized that Gabriele had to be the source of the leaks, because some documents had clearly been taken from a desk that only Gaenswein and Gabriele had access to.
That led to an Agatha Christie-like moment in the pope's apartment when Gaenswein summoned all of the papal employees into a room and asked each one: "Did you steal the documents?" Everyone, including Gabriele, denied it.
Several days later, 82 cardboard boxes of evidence were removed from the Vatican apartment Gabriele shares with his wife and three children. Again today Gabriele insisted he was acting entirely on his own, but few Vatican observers believe that.
"I think the butler is too simple a person to do something on his own," papal biographer Marco Politi said. "If it happened, there are others helping him and maybe leading him."
Vatican spokesman Father Federico Lombardi said Gabriele did not have malicious intent.
"Paolo Gabriele has clearly admitted having committed the act, to having collected and brought these confidential documents out. He stated that he did not act for economic gain, but because of the personal unease he was living in and feeling around him," he said.
The trial is scheduled to continue Wednesday and again on Friday when it may conclude.
Vatican sources say if Gabriele is found guilty he is almost certain to be pardoned by the pope.