As a general proposition, anything that a party to an action has voluntarily said at any time, if relevant, will be admissible against him. In the case of two types of such statements, ordinary direct admissions and voluntary confessions, the legal principles and rationales underlying their admissibility are so well-recognized and self-evident as to occasion little confusion and less need for comment. However, in cases where a person is sought to be charged with a statement made by someone else (the so-called implied or adoptive admissions and the various types of vicarious admissions), the underlying rationalizations and applications of the rules are more difficult and subtle, although equally valid and well-recognized.
Charles W. Blicker II,
Use of Confessions and Admissions of a Codefendant in Washington,
24 Wash. L. Rev. & St. B.J.
Available at: https://digitalcommons.law.uw.edu/wlr/vol24/iss1/5