Perjury is the crime of making a knowingly false statement which bears on the outcome of an official proceeding that is required to be testified to under oath. A statement is made under oath when 1) the statement was made on or pursuant to form bearing notice, authorized by law, to the effect that false statements made therein are punishable, or 2) the statement recites that it was made under oath, the declarant was aware of such recitation at the time he made the statement and intended that the statement should be represented as a sworn statement, and the statement was signed by an officer authorized to administer oaths.
An oath of truthfulness may be made to a notary public, court clerk or other official. False statements under oath made in testimony in court, administrative hearings, depositions, answers to interrogatories, as well as by signing or acknowledging a written legal document (such as affidavit, declaration under penalty of perjury, deed, license application, tax return) are subject to prosecution for perjury under various state and federal laws.
Penalties for perjury vary greatly, and may be charged as a misdemeanor or felony depending on the facts and law involved. Multiple perjury convictions can result from statements made in the courtroom or in a court proceeding which follow the taking of an oath. Separate false statements may be charged in separate perjury counts if they require different factual proof of their falsehood, even if they are related to the same subject matter.