Mea Maxima Culpa investigates the secret crimes of Father Lawrence Murphy, a charismatic Milwaukee priest who abused more than 200 deaf children in a school under his control. The film documents the first known public protest against clerical sex abuse in the U.S., which led to a case that spanned three decades and ultimately resulted in a lawsuit against the pontiff himself. The investigation helped uncover documents from the secret Vatican archives that show the Pope, who must operate within the rules of the Roman Curia, as both responsible and helpless in the face of evil.