Any person punishable under this chapter who—

commits an offense punishable by this chapter, or aids, abets, counsels, commands, or procures its commission; or

causes an act to be done which if directly performed by him would be punishable by this chapter;

Article 77 does not define an offense. Its purpose is to make clear that a person need not personally perform the acts necessary to constitute an offense to be guilty of it. A person who aids, abets, counsels, commands, or procures the commission of an offense, or who causes an act to be done which, if done by that person directly would be an offense, is equally guilty of the offense as one who commits it directly, and may be punished to the same extent. Article 77 eliminates the common law distinctions between principal in the first degree (“perpetrator”); principal in the second degree (one who aids, counsels, commands, or encourages the commission of an offense and who is present at the scene of the crime— commonly known as an “aider and abettor”); and accessory before the fact (one who aids, counsels, commands, or encourages the commission of an offense and who is not present at the scene of the crime). All of these are now “principals.”

A perpetrator is one who actually commits the offense, either by the perpetrator’s own hand, or by causing an offense to be committed by knowingly or intentionally inducing or setting in motion acts by an animate or inanimate agency or instrumentality which result in the commission of an offense. For example, a person who knowingly conceals contraband drugs in an automobile, and then induces another person, who is unaware and has no reason to know of the presence of drugs, to drive the automobile onto a military installation, is, although not present in the automobile, guilty of wrongful introduction of drugs onto a military installation. (On these facts, the driver would be guilty of no crime.) Similarly, if, upon orders of a superior, a soldier shot a person who appeared to the soldier to be an enemy, but was known to the superior as a friend, the superior would be guilty of murder (but the soldier would be guilty of no offense).

If one is not a perpetrator, to be guilty of an offense committed by the perpetrator, the person must:

Assist, encourage, advise, instigate, counsel, command, or procure another to commit, or assist, encourage, advise, counsel, or command another in the commission of the offense; and

Share in the criminal purpose or design. One who, without knowledge of the criminal venture or plan, unwittingly encourages or renders assistance to another in the commission of an offense is not guilty of a crime. See the parentheticals in the examples in subparagraph 1.b.(2)(a) of this paragraph. In some circumstances, inaction may make one liable as a party, where there is a duty to act. If a person (for example, a security guard) has a duty to interfere in the commission of an offense, but does not interfere, that person is a party to the crime if such a noninterference is intended to and does operate as an aid or encouragement to the actual perpetrator.

Presence at the scene of the crime is not necessary to make one a party to the crime and liable as a principal. For example, one who, knowing that a person intends to shoot another person and intending that such an assault be carried out, provides the person with a pistol, is guilty of assault when the offense is committed, even though not present at the scene.

Mere presence at the scene of a crime does not make one a principal unless the requirements of subparagraph 1.b.(2)(a) or (b) have been met.

When an offense charged requires proof of a specific intent or particular state of mind as an element, the evidence must prove that the accused had that intent or state of mind, whether the accused is charged as a perpetrator or an “other party” to crime. It is possible for a party to have a state of mind more or less culpable than the perpetrator of the offense. In such a case, the party may be guilty of a more or less serious offense than that committed by the perpetrator. For example, when a homicide is committed, the perpetrator may act in the heat of sudden passion caused by adequate provocation and be guilty of manslaughter, while the party who, without such passion, hands the perpetrator a weapon and encourages the perpetrator to kill the victim, would be guilty of murder. On the other hand, if a party assists a perpetrator in an assault on a person who, known only to the perpetrator, is an officer, the party would be guilty only of assault, while the perpetrator would be guilty of assault on an officer.

A principal may be convicted of crimes committed by another principal if such crimes are likely to result as a natural and probable consequence of the criminal venture or design. For example, the accused who is a party to a burglary is guilty as a principal not only of the offense of burglary, but also, if the perpetrator kills an occupant in the course of the burglary, of murder. (See also paragraph 5, Conspiracy, concerning liability for offenses committed by co-conspirators.)

One may be a principal, even if the perpetrator is not identified or prosecuted, or is acquitted.

A person may withdraw from a common venture or design and avoid liability for any offenses committed after the withdrawal. To be effective, the withdrawal must meet the following requirements:

It must occur before the offense is committed;

The assistance, encouragement, advice, instigation, counsel, command, or procurement given by the person must be effectively countermanded or negated; and

The withdrawal must be clearly communicated to the would-be perpetrators or to appropriate law enforcement authorities in time for the perpetrators to abandon the plan or for law enforcement authorities to prevent the offense.