The Catholic Archdiocese of Philadelphia supplied a priest accused of sexually abusing and assaulting young teenage boys with an “endless” supply of victims through assignments that involved ministering to youth, a Philadelphia prosecutor argued in court Monday.

In an unprecedented step nationally, the Philadelphia District Attorney’s Office has charged the priest’s supervisor, the Catholic Archdiocese of Philadelphia’s former personnel director for priests, Monsignor William Lynn, with two counts of endangering the welfare of a child and two counts of conspiracy for allegedly failing to protect children by moving two accused sexual offenders to new parish assignments.