Unit 25: Conspiracy I


  • Dressler 401-411

  • Azim (CP)

  • Castro (CP)

Key words: 

  • conspiracy

  • corrupt-motive doctrine


A conspiracy is an agreement, express or implied, to commit an unlawful act or series of unlawful acts.

The essence of conspiracy is agreement. An agreement can exist even if the parties do not know every detail of the criminal plan, as long as the parties are aware of the essential nature of the crime.

The agreement itself is often proven through circumstantial evidence, and can be inferred from different parties performing a coordinated series of acts.

Why Punish Conspiracy?

One reason to criminalize conspiracy is that agreeing to commit a crime demonstrates the actor’s dangerous disposition. Conspiracy also relies on the idea that collective criminal agreement increases the likelihood that a criminal objective will be achieved, because one is less likely to abandon the crime in a group setting (out of fear, loyalty, or camaraderie) and division of labor makes crime more efficient. However, some critics have argued that the more people involved in a crime, the more likely someone will try to convince the group to desist or inform the police.

Criminalizing conspiracy raises the same policy tradeoff considerations as other inchoate crimes: the need of the police to prevent crimes weighed against the risk of punishing an innocent actor.

Common Law Conspiracy: Actus Reus

At common law, conspiracy was graded as a misdemeanor, regardless of whether the target offense was a felony. Conspiracy did not merge with the target offense, so a person could be convicted of both conspiring to commit an offense and the target offense itself (or attempt of the offense) based on the same set of facts. Today, most states grade conspiracies in relation to the target offense, so that the conspiracy to commit a felony is a felony (though usually a less severe felony than the target offense).

The actus reus of conspiracy at common law is satisfied by an agreement to commit a crime or to commit a lawful act through corrupt, dishonest, fraudulent, or immoral means. Under the “lawful act through unlawful means” definition of conspiracy, someone could be punished for an act that would not have been illegal if done by one person. For example, a conspiracy to commit a noncriminal tort (such as defamation or fraud) would result in criminal liability for conspiracy at common law. An agreement to commit an immoral act could also result in criminal liability for conspiracy at common law: for example, an agreement to persuade a woman to leave her father’s home and live in fornication or an agreement to engage in prostitution constituted conspiracy in the 1800s, even though prostitution was not criminalized. Critics of this definition of conspiracy argue that it violates fair notice, the legality principle, and the Fifth and Fourteenth Amendment’s due process guarantee. Today, most states do not recognize an agreement to commit a lawful act through unlawful means as a valid conspiracy.

Although common law conspiracy did not require an overt act in furtherance of the conspiracy, most jurisdictions today require such an act in addition to the agreement. The overt act need not satisfy the actus reus of an attempt. Any act, no matter how trivial (even “mere preparation”), is enough to satisfy the overt act requirement. Furthermore, only one party to a conspiracy needs to commit an act. The overt act requirement is intended to ensure that society does not punish innocent actors and that a conspiratorial agreement is more than just banter.

MPC Actus Reus

Under MPC 5.05(1), conspiracy is graded at the same level as the most serious target offense the parties conspired to commit (except for first degree felonies, for which conspiracies are graded as second degree felonies).

Conspiracy merges with the target offense under MPC 1.07(1)(b), but if the conspirators are caught after the completion of one offense, and they had agreed to commit more crimes, then they could be convicted of both the completed offense and the conspiracy to commit additional crimes. If the offense is not one of the first or second degree, the overt act requirement can be met by the completed offense.

An agreement to commit, attempt to commit, solicit, or aid in the commission of a crime satisfies the actus reus of conspiracy under MPC 5.03(1); unlike common law conspiracy, an agreement to commit a lawful act by unlawful means does not constitute a conspiracy.

If the target offense is a first or second degree crime, an overt act is not required; for lesser degree target offenses, there must be an overt act. See MPC 5.03(5).


Under MPC 5.03(6), abandonment is an affirmative defense to conspiracy. A co-conspirator must completely and voluntarily renounce his criminal purpose, and must also thwart the criminal objective.

The common law does not recognize abandonment as an affirmative defense to conspiracy.

Questions for Review:

Q1. If you were the defense attorney for Azim, what facts would you emphasize when arguing that he was not a part of the conspiracy?

Q2. What are the major differences between conspiracy as defined at common law and by the MPC?