In 2002, as the Boston Globe's reporting on clergy sexual abuse spread from Boston to dioceses across the country, the United States Conference of Catholic Bishops commissioned researchers at John Jay College of Criminal Justice to answer a question nobody had ever tried to answer at national scale: how many priests, and how many victims. The method was a survey, sent to every US diocese and religious order, asking each to report what its own files held on allegations of child sexual abuse by clergy.
The result, published in 2004, was the first national count. Dioceses identified 4,392 priests accused of abusing a minor and 10,667 separate allegations, spanning 1950 to 2002, roughly four percent of the priests active in the United States over that period. The study also documented the pattern that would recur in every inquiry that followed: known abusers routinely reassigned to new parishes rather than removed from ministry.
The report's own honest limit is its method. It counted what dioceses chose to report from their own records, not what an independent audit of those records would have found, so its authors and the researchers who have used it since treat 4,392 as a floor rather than a ceiling. Later inquiries in Pennsylvania, Ireland, Australia and France, each working from subpoenaed or independently examined archives, would go on to find the same pattern of concealment the John Jay survey could only partially see from the outside.