Purgatory Oath Law and Legal Definition
A purgatory oath refers to an oath by which a person destroys the presumptions which were against him/her. Such a person is said to purge himself/herself when s/he removes the suspicions which were against him/her. For example, if a person faces contempt for not attending court as a witness, s/he may purge himself/herself of the contempt by swearing to a fact which is an ample excuse.
A purgatory oath allows defendants to obtain an acquittal by swearing to their own innocence. [United States v. Gecas, 120 F.3d 1419, 1438 (11th Cir. Fla. 1997)]