The criminal offense of perjury consists of making a false statement under oath, either in writing or verbally, that one knows is false, and that is material to the proceedings in which the statement is made. The definition of perjury is therefore much more complicated than many people realize. It requires proof of more than just a false statement in a court proceeding or otherwise under oath. In a sense, a person must make a false statement with an intent to defraud.

Definition of Perjury

Federal law defines two types of perjury, each of which has multiple elements. The first type of perjury involves statements made under oath, and requires proof that:

• A person took an oath to truthfully testify, declare, depose, or certify, verbally or in writing;
• The person made a statement that was not true;
• The person knew the statement to be untrue;
• The person made the false statement willfully; and
• The subject matter of the statement was material to the proceeding in which it was made.

The second type of perjury involves unsworn statements, and requires proof that:

• A person made an unsworn declaration as permitted by federal law;
• The statement was made “under penalty of perjury”;
• The person willfully made a statement that he or she did not believe to be true; and
• The subject matter of the statement was material.

State laws defining perjury are generally similar to the federal statute. Ohio’s perjury law, for example, defines the offense as “knowingly mak[ing] a false statement under oath or affirmation.” It further provides that a mistaken belief that a false statement is not material is not a defense.

Knowledge of Falsity

The specific act that constitutes the crime of perjury is not the false statement itself, but rather the oath or affirmation that the statement is true.

Most perjury statutes require proof that a person acted with knowledge of the falsity of the statement. The federal statute requires that a person acted “willfully,” while Ohio’s statute says the person must have acted “knowingly.” Defendants may claim that they believed the statement to be true, and that they therefore did not have the required mental state.

Materiality of Statement

The requirement that a false statement is material to the proceeding may be the most important element of perjury. Ohio’s perjury statute defines “material” as something that could “affect the course or outcome of the proceeding.” The U.S. Supreme Court defined it, in Kungys v. United States, as a statement that “has a natural tendency to influence, or was capable of influencing, the decision of the decision-making body to which it was addressed.”(internal quotation marks omitted).

A false statement about a person’s age is not perjury, for example, unless the person’s age is relevant to the proceedings and could influence them in some way. This could be the case if a person lied about his or her age in an application for public benefits based on age, in which case the person might have also committed welfare fraud.

Subornation of Perjury

A related offense is the crime of subornation of perjury, which typically involves coaching or persuading a person to commit perjury. Attorneys and other people who might advise a witness may be targets of subornation of perjury accusations.

Last updated May 2019