A statement that has been signed by a declarant who will be found guilty of perjury if the facts declared in the statement are shown to be materially false. These statements have the same effect as an affidavit does in federal court. An affidavit is one example of a declaration that is sworn, typically before a notary or officer of the court. Additionally, a declaration under penalty of perjury can also be unsworn. For example, 28 U.S.C. § 1746 details that matters that must be satisfied by a sworn declaration or affidavit may also be satisfied by an unsworn declaration made under penalty of perjury.
[Last updated in June of 2020 by the Wex Definitions Team]