Canon Law (the legal code of the Catholic Church) says a postulator's job is to "examine, collect and research historical and theological material about the individual for whom the honors of the altar are sought and to present that case to the bishop of the diocese and Holy See."

Dr. Andrea Ambrosi began his work as Roman Postulator in the early 1980s and estimates that he has handled more than 300 cases.

One of Dr. Ambrosi's most importaont functions in the early years was to play Devil's Advocate, and not just as a generic figure of speech. As part of the ancient, protracted and labyrinthine Church process of beatification and canonization, there is always an official "accuser" whose job is to try to rip a case to shreds.

"It was incredible training," said Dr. Ambrosi. "Because to be a good defender, you have to know how to be a good accuser."

In the world, there are perhaps only 30 people who do what Dr. Ambrosi does. But since Dr. Ambrosi spent three years playing Devil's Advocate and gaining invaluable experience with the General Promoter of the Faith, a Vatican position within the Congregation for the Causes of Saints, by the time John Paul II instituted his sweeping procedural changes, he was a seasoned pro.

http://www.archbishopsheencause.org/bishopjenky.html