By Jason Horowitz
VATICAN CITY — David Kertzer put down his cappuccino, put on his backpack and went digging for more Vatican secrets.
“There’s an aspect of treasure-hunting,” said Kertzer, a 74-year-old historian.
Moments later, he cut through a crowd lined up to see Pope Francis, showed his credentials to the Swiss Guard and entered the archives of the former headquarters for the Holy Roman Inquisition.
Over the last few decades, Kertzer has turned the inquisitive tables on the church. Using the Vatican’s own archives, the soft-spoken Brown University professor and trustee at the American Academy in Rome has become arguably the most effective excavator of the Vatican’s hidden sins, especially those leading up to and during World War II.