The Priest Penitent Privilege (now known as the Clergy-Penitent Privilege) is a rule of evidence that protects the confidential communication shared between a priest or clergyman and a penitent or communicant. The privilege provides an exemption for clergy members from the duty to disclose evidence in a court of law. This privilege is claimed in two contexts: to prevent disclosure of confidential information at trial as well as to exempt clergy from the duty to report child abuse. The latter context for the claiming of this privilege seems to be most at issue today.
Black's Law Dictionary
Privilege: An evidentiary rule that gives a witness the option to not disclose the fact asked for, even though it might be relevant; the right to prevent disclosure of certain information in court, esp. when the information was originally communicated in a professional or confidential relationship. • Assertion of an evidentiary privilege can be overcome by proof that an otherwise privileged communication was made in the presence of a third party to whom the privilege would not apply.
PRIVILEGE, Black's Law Dictionary (11th ed. 2019)
Priest-penitent privilege (1958): The privilege barring a clergy member from testifying about a confessor's communications. -- Also termed clerical privilege; minister's privilege; clergyman-penitent privilege.
A religious right later considered to be protected under the Free Exercise Clause, the privilege was originally known as the priest-penitent privilege. This privilege originated to protect communication revealed in the sacrament of confession. Because confession was an essential part of the Catholic religion and an essential duty of a priest, courts and legislatures recognized the necessity of protecting this religious practice. In 1813, in the case People v. Philips, New York recognized a privilege for priests when the communication in question was obtained in the sacrament of Confession. The court ensured a priest's right to freely exercise his religion in protecting the seal of confession. Concerning other clergyman, the New York court later held that the same privilege was not conferred to a Protestant because his religion did not have the sacrament of Confession.
This summary was based on the article Breaking the Seal of Confession: Examining the Constitutionality of the Clergy Penitent Privilege in Mandatory Reporting Law by Caroline Donze.
Over time, the privilege was broadened to include communication shared in confidence between a communicant and clergyman of other faiths. The privilege was generalized in most states to encompass all faiths equally. States vary in their inclusion of the privilege, some taking a broad approach, others narrow. The treatise, Testimonial Privileges, represents this well in its comparison of two state statutes:
One relatively narrow statement of the privilege is contained in the Idaho statute: “A clergyman or priest cannot, without the consent of the person making the confession, be examined as to any confession made to him in his professional character in the course of discipline enjoined by the church to which he belongs.”4 An example of a broad version of the privilege is found in the Minnesota statute: “… nor shall a member of the clergy or other minister of any religion be examined as to any communication made to the member of the clergy or other minister by any person seeking religious or spiritual advice, aid, or comfort or advice given thereon in the course of the member of the clergy's or other minister's professional character, without the consent of the person.”5
§ 6:3. Clergy communication privilege in state courts, 2 Testimonial Privileges § 6:3 (3d ed.)