According to a 2004 research study by the John Jay College of Criminal Justice for the United States Conference of Catholic Bishops, 4,392 Catholic priests and deacons in active ministry between 19 have been plausibly (neither withdrawn nor disproven) accused by 10,667 individuals of the sexual abuse of a youth under the age of 18.
The Commission revealed 7% of Australian priests between 1950–2009 were accused of abusing children, and that one Catholic order had 40.4% of their non-ordained members with allegations against them in this period.
Many of the cases span several decades and are brought forward years after the abuse occurred.
Although nationwide inquiries have been conducted only in the United States and Ireland, as well as an Australian inquiry into institutional responses, cases of clerical sexual abuse of minors have been reported and prosecuted in New Zealand, Canada and other countries.
In a series of letters and reports to high-ranking Catholic leaders starting in the 1950s, Fitzgerald warned of substantial problems with pedophile priests.
He wrote, for example, "[sexual abuse] offenders were unlikely to change and should not be returned to ministry." He discussed the problem with Pope Paul VI (1963 – 1978) and "in correspondence with several bishops".