Declaration against interest

In United States law, a declaration (or statement) against interest is an exception to the rule on hearsay in which a person's statement may be used, where generally the content of the statement is so prejudicial to the person making it that they would not have made the statement unless they believed the statement was true. For example, if a driver in an automobile accident boasts publicly that they were speeding, it may represent a legal admission of liability.

Source: Wikipedia — Declaration against interest (CC BY-SA 4.0)