Perjury | Definition

Doc's CJ Glossary by Adam J. McKee
Course: Criminal Law

Perjury is lying under oath, knowing the information is false, about a material issue in a legal proceeding.

Perjury, put simply, is the act of lying or making false statements while under oath. This is considered a serious offense because it threatens the integrity of the legal process. The key aspect is that the individual must knowingly lie about something that matters, or is “material,” in the legal proceeding. Let’s dive deeper into understanding perjury.

When Does Perjury Occur?

Perjury occurs in many different scenarios but always involves a formal setting where someone is under oath. It could happen during a court trial, a deposition (which is a sworn statement given before trial), or even when someone is providing sworn written testimony. After all, these are instances where the person has sworn to tell the truth, the whole truth, and nothing but the truth.

Materiality: A Key Component

A crucial element in perjury is the concept of “materiality.” Not all lies are considered perjury. For instance, if a person lies about their favorite color while under oath, it likely won’t qualify as perjury. It’s neither relevant nor material to the outcome of the proceedings. If, however, the person lies about witnessing a crime, that lie could affect the outcome. In that case, the false statement is material and can be considered perjury.

The Consequences of Perjury

Above all, it’s essential to understand that perjury is a crime. It’s taken seriously because it undermines the trust in our legal system. If a person is found guilty of perjury, they can face severe penalties, including fines and jail time. Both the accused and the legal system are victims of this crime. The accused because their fate might be determined based on false information, and the legal system because its purpose is to uncover the truth.

Defending Against Perjury Accusations

If accused of perjury, a person has several potential defenses. One common defense is that the person didn’t know the information was false when they said it. After all, to commit perjury, a person must knowingly lie. Another defense might be that the lie wasn’t about a material issue.

The Critical Role of Perjury in Criminal Justice

All in all, perjury plays a critical role in the field of criminal justice. It’s designed to maintain the integrity of our legal system, ensuring that people tell the truth when it matters most. After all, whether it’s in a court of law or during a deposition, truthfulness is essential for justice to be served.

Perjury under Common Law

Blackstone’s Commentaries on the Laws of England provide an excellent historical source for understanding how perjury was treated under common law. Blackstone, a renowned legal scholar, had a significant impact on the development of English law, and his commentaries continue to influence legal systems based on common law, such as the United States.

According to Blackstone, perjury was considered a grave moral offense as well as a serious crime under common law. Perjury disrupts the process of justice by providing the courts with false evidence, making it difficult for justice to be properly served. He described it as an “act of notorious profligacy and falsehood” and “a crime of a deep and destructive nature.”

Under common law, a person was guilty of perjury if they made a false statement, under oath, in a judicial proceeding, about a material fact. The oath was seen as a sacred vow, and to break it was to insult the divine, as well as to obstruct the earthly pursuit of justice.

The punishment for perjury under common law was severe. Blackstone’s Commentaries indicate that those found guilty of perjury could face various penalties, including imprisonment and fines. There were even instances where individuals convicted of perjury were sentenced to pillory, a form of public humiliation and physical discomfort. However, the exact punishment could vary, depending largely on the severity and impact of the perjury.

In summary, Blackstone’s Commentaries on common law reveal the historical gravity of perjury. The crime of lying under oath, especially about a matter that could impact the outcome of a trial, was taken very seriously. The tradition of stringent penalties for perjury was carried forward from common law into modern legal systems, illustrating the enduring importance of truthfulness in legal proceedings.

How the Model Penal Code (MPC) Treats Perjury

The Model Penal Code (MPC), a guideline used to standardize legal principles across different states, also addresses perjury. It provides a basis for understanding this crime and helps ensure a consistent application of the law. Let’s explore how the MPC handles perjury.

According to the MPC, a person is guilty of perjury if, in any official proceeding, they make a false statement under oath, or they swear or affirm the truth of a statement previously made, and they do not believe the statement to be true. The lie must be about a matter for which the truth is required.

The MPC not only considers lying under oath as perjury but also making inconsistent statements in different official proceedings. If a person, under oath, makes two or more declarations that are inconsistent to the degree that one of them is necessarily false, they can be charged with perjury, even if it can’t be determined which statement is false. This approach is known as the “two-witness” rule and demonstrates the thoroughness of the MPC.

The penalty for perjury under the MPC is typically categorized as a felony, indicating its seriousness. The suggested sentence, according to the MPC, is imprisonment, the length of which can vary depending on the jurisdiction.

Moreover, the MPC asserts that truthfulness is the cornerstone of the legal process. It clarifies that “materiality,” the concept that the false statement must relate to a significant or relevant issue, is not determined by the potential outcome of the specific case, but rather whether the lie could possibly affect the proceeding in which it was made.

All in all, the MPC offers comprehensive and clear guidelines for understanding and prosecuting perjury, reinforcing the essential role of truthfulness in the judicial process.

Elements of Perjury

Mens Rea (Guilty Mind): For perjury to occur, the individual must knowingly make a false statement. It’s not enough to say something untrue; the person must be aware that what they’re saying is false at the time they say it.

Actus Reus (Guilty Act): The guilty act is the act of lying under oath during an official proceeding. A false statement, or affirmation of a previous false statement, constitutes the actus reus.

Concurrence: The guilty mind (mens rea) and the guilty act (actus reus) must occur simultaneously. In other words, the person must be aware that their statement is false at the same time they make it under oath.

Causation: N/A – The concept of causation, which usually links a specific action to a harmful result, isn’t applicable in perjury cases. The crime lies in the act of lying under oath itself, not in any specific harm that might result from the lie.

Harm:  No actual harm needs to occur.

Attendant Circumstances: The false statement must be made under oath during an official proceeding. It also needs to be material, meaning it could affect the proceeding’s outcome.

Additionally, perjury under the Model Penal Code can occur if a person makes inconsistent statements under oath, one of which is necessarily false, even if it isn’t clear which statement is false.


Learn More

On This Site

[ Glossary ]

Last Modified: 03/10/2023


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.