Judge John Heyburn allowed three men to begin collecting evidence to support their charge that Vatican officials were negligent in protecting them from abusive clerics. The ruling would allow the plaintiffs to demand documents from the Vatican and take testimony from officials in Rome.
Judge Heyburn based his ruling on the plaintiffs' claim that the American bishops were acting as agents or employees of the Holy See when they allowed known abusers to remain in clerical ministry.
In his ruling the judge reported that lawyers for the Church had declined to contest that claim. If the Holy See can demonstrate that US bishops are not Vatican employees, he said, the ruling could be reconsidered.
The Kentucky ruling marks the first time that an American court has allowed plaintiffs to pursue a sex-abuse lawsuit in which the Vatican is the sole defendant.
In past cases, lawyers for the Church have argued successfully that the Holy See is immune from suits as a sovereign power. In this case the court found that - if the US bishops are Vatican employees - the case could qualify for treatment under US law allowing suits against sovereign powers whose employees or agents cause harm while acting in their official capacities.
While allowing the plaintiffs to proceed with their efforts to demonstrate negligence on the part of the Vatican, the judge threw out two other claims, which had alleged that the Vatican engaged in deceit about sexual abuse and failed to protect children under the care of the Church. The decision by Judge Heyburn in a US district court is likely to be appealed.