Perjury, the crime of false swearing. He commits perjury who, under oath lawfully administered in a judicial proceeding or course of justice, wilfully gives false testimony material to the issue or point in question. The offence is thus defined at common law. In many of the United States it is particularly defined by statutes; and these extend the definition, and in some cases make it embrace all false oaths corruptly taken, where an oath by law is required or authorized, whether in judicial proceedings or not. It may be said generally that wherever, under the common law of the land, an oath is required in the regular administration of justice, there the crime is possible. The offence cannot be founded on the violation of a mere oath of office. For example, an officer, public or private, who neglects to execute his office in pursuance of his oath, or acts contrary to the tenor of it, is not indictable for perjury. Nor can the common law offence consist of the violation of an oath taken in any purely extra-judicial proceeding; as a false affidavit to an account to be rendered by an administrator, or false swearing before a justice of the peace, before whom no cause in any stage is pending.

So, though false testimony given before a commissioner appointed by a court under the common rule is perjury, yet it is not so when given in depositions taken by consent before unauthorized persons. It matters not whether the untrue evidence was given in the principal investigation of the matter in issue, or whether it was in some preliminary or incidental proceeding. Not only, therefore, may it be committed by a witness who is giving oral testimony in a trial in open court, but it may be as well in the preliminary information or complaint before a magistrate, or in statements made before the grand jury, or in a deposition made before a commissioner duly authorized to take it. So the examination of a poor debtor before a magistrate is a course of justice, and false swearing there is perjury. The hearing of a cause must furthermore be really, not apparently only, a judicial proceeding. For, if a judge who seemed to have authority, yet had none in fact, administered the oath, or if a suit, though properly brought, had yet in fact abated by the death of a party, and thus passed out of the court's jurisdiction, false swearing in either case is not indictable. But perjury is not excused if the pleadings were merely informal and amendable, or if the proceedings were voidable but not void.

It is further essential that an oath was lawfully administered. The indictment therefore usually recites that the party was in due manner sworn and took his corporal oath to speak the truth. It is enough, however, to avow that the party was duly sworn, without alleging the mode in which the oath was administered. Yet, if the allegation be of a specific mode, a variance in the proof will be fatal; and perhaps the indictment would fail if it charged that the party was sworn, when in fact he only made solemn affirmation of the truth. The oath, as we have already implied, can be well administered only by competent authority, and before a court or magistrate having legal right to proceed in the cause. It suffices in the indictment to allege this competent power and authority, without setting forth the facts which constitute jurisdiction. - In proof of the falsity of the testimony, which is also an essential element of the offence, it is not requisite to recite the exact words uttered, with the same nicety as in the case of forgery or libel. It is sufficient to allege substantially what the defendant said as to the matter in question, and that he knew it to be false. The false testimony must be given wilfully.

It has sometimes been held that the allegation of wilful and corrupt falsehood is well supported by evidence that the accused swore rashly to that which he did not know, and, though he believed it, yet had no probable cause for believing. But the better opinion seems to be, that perjury is not committed if the party gave his testimony in accordance with his belief,, no matter how carelessly or rashly that belief may have been formed. In other words, a distinct corrupt intent is essential to the crime. - Finally, the false testimony must be material to the point in controversy. The degree of materiality is of no importance, nor is it necessary that the false declaration immediately and directly touch the issue; it suffices if it remotely or collaterally affect it. Perjury then may be committed, if the testimony tend to increase or diminish the damages or punishment, or if it concern the credibility of the witness himself, or of any other witness in the case. A false answer to a question put by way of cross examination may therefore lay the foundation of an indictment; and it has been held to be perjury where a party, after being particularly cautioned as to his reply, answered falsely to an interrogatory, put merely with the design of impairing his credit as to that part of the evidence which was immediately material.