Concept
The Model Penal Code Definition
Elements of Conspiracy
The Model Penal Code Definition
The Model Penal Code keeps agreement at the center of conspiracy and restates it more exactly than the common-law formula does. Section 5.03(1) makes a person guilty of conspiracy to commit a crime if, acting with a stated purpose, the person either agrees with others that one or more of them will engage in conduct constituting the crime or an attempt or solicitation to commit it, or agrees to aid them in planning or committing the crime or such an attempt or solicitation.1 The definition is easiest to learn in layers. The lead-in fixes the mental state and governs both alternatives, so it comes first, and each alternative then takes its own turn.
Three departures from the common law run through that text. The first concerns the object: the definition speaks only of conspiracy to commit a crime, which writes the modern criminal-object limit directly into the offense and leaves no room for noncriminal wrongs.2 The second concerns grammar, because liability is framed around what one defendant agrees to and wants rather than around a combination of several people. The third concerns aid, which receives its own branch. The rest of § 5.03 (the scope of the conspiratorial relationship, multiple objectives, joinder and venue, the overt-act requirement, renunciation, and duration) is taught in other readings, and this section stays with subsection (1).3
The Purpose Requirement
The lead-in supplies the mental state for the whole offense. A person is guilty only if the person acts "with the purpose of promoting or facilitating its commission," and "its" refers to the crime that is the object of the agreement.4 The lead-in ends with a colon and is followed by two alternative ways of conspiring, so the purpose attaches to each of them. A defendant who agrees to commit a crime, or to help others commit one, without that purpose has satisfied neither branch.
The Code compresses the common-law mental state into one phrase. Courts that call conspiracy a specific-intent crime usually divide the mental state into two parts, an intent to agree and an intent to commit the offense that is the object of the agreement.5 The Code's phrase supplies the second part directly and leaves the first to the verb agrees. It also states that second part in terms of aim: the defendant must want the crime promoted or facilitated. Knowing that others will commit a crime is a weaker state of mind than wanting the crime to happen, and the earlier discussion of intent versus knowledge showed why that gap matters. The Code closes the gap in favor of purpose.
The reason for demanding purpose is easiest to see from the position of someone who deals with a wrongdoer in the ordinary course of business. Conspiracy punishes a plan before any harm has occurred, so the defendant's state of mind is the only thing separating a partner in the venture from a bystander who happened to learn of it. If knowledge were enough, a merchant who filled an ordinary order after hearing a customer's criminal plans would be a conspirator, and every merchant would have to investigate customers' affairs to stay safe. Against that burden on legitimate trade stands the interest in reaching people who knowingly supply a crime. The Code resolves that tension for accomplices by requiring the purpose of promoting or facilitating the offense, after the American Law Institute rejected the early proposals, and the conspiracy lead-in uses the same phrase.6
The lead-in is also worded around a single defendant. It asks when a person is guilty of conspiracy with another person or persons, and the inquiry that follows concerns what that person agrees to and wants.7 That is the sense in which the Code builds the offense around the individual's purpose and commitment to a crime. On a problem with several defendants, each defendant's purpose is therefore analyzed separately, and the presence of other guilty participants does not supply it.
The two sales differ in a single respect, whether the seller's aim is tied to the crime. Knowing that a customer plans a crime does not satisfy the lead-in, and a sale in the ordinary course of business does not by itself show the seller shares the customer's aim. Facts such as a specially tailored order or a price raised to cover legal risk are the kind of circumstances that bear on whether a supplier has joined the venture.8 On an exam, state the purpose requirement before analyzing either branch, because a defendant who fails it escapes both.
Agreeing That a Crime Occurs
Subsection (1)(a) states the first way to conspire: the defendant agrees with one or more other persons that they, or one or more of them, will engage in conduct that constitutes the crime or an attempt or solicitation to commit it.10 Three requirements are packed into that sentence, and each has its own job. The defendant must reach an agreement, meaning a commitment to a shared plan, with at least one other person. The agreement must concern future conduct that would itself be a crime, which carries the criminal-object limit into the text of the branch. And the conduct may be performed by the defendant, by someone else in the group, or by several of them, because the text speaks of the parties collectively or any one or more of them.
That last feature matches how criminal ventures actually operate. Participants divide the labor: one enters, one drives, one finances, one disposes of the proceeds. If the offense required each defendant to agree to perform the criminal conduct personally, the organizer who never leaves home would escape. The wording instead ties liability to what the defendant agreed would happen, namely that someone in the group will carry out the crime, so an organizer who stays away is as much a party to that agreement as the person who goes in. The offense is also measured by the agreement and not by the result, since the text looks to conduct the parties will engage in, and the crime itself never has to occur.
The object extends beyond the completed crime to an attempt or a solicitation to commit it. Two people who agree that one of them will attempt a burglary, or will solicit a third person to commit one, have agreed to conduct that is a crime in its own right. The reach follows from the structure of the definition, which classifies an agreement by the conduct the parties agree will be done, and an attempt or solicitation, once carried out, is such conduct.11
The flipped version differs from the first in only one fact, whether the agreed conduct is criminal, and that fact decides the outcome. The analysis on a stem like this proceeds in two steps. First identify the conduct the parties agreed would occur and ask whether it constitutes a crime, an attempt, or a solicitation. Then ask only whether the defendant agreed to the occurrence of that conduct, because who will perform the conduct does not matter under this branch.
Agreeing to Aid
Subsection (1)(b) gives the second way to conspire: the defendant agrees to aid another person or persons in the planning or commission of the crime, or of an attempt or solicitation to commit it.13 The same lead-in purpose governs this branch. The two branches measure different things. Branch (a) is framed around what the group agrees will be done, while branch (b) is framed around what this defendant promises to contribute, so a helper whose role is only to assist can be reached without any finding that the helper agreed to perform the crime. The aid may come before the crime, as when someone prepares a floor plan or tracks a guard's schedule, or during it, as when someone supplies the getaway car.
Two features of the text deserve attention. The aid itself may be lawful in form, since a drawing or a schedule is not a crime, and what makes the promise culpable is the purpose behind it and the criminal object it serves. The conduct the definition names is also the agreement to aid, and not the delivery of aid, so the helper's promise is the operative event. Whether a further overt act must be proved depends on subsection (5), which dispenses with an overt act for conspiracies to commit first- and second-degree felonies and requires one for other crimes, a point taught elsewhere.14
This branch is the conspiracy counterpart of accomplice liability. An accomplice actually aids a crime, and the Code requires the accomplice to act with the purpose of promoting or facilitating it.15 Subsection (1)(b) uses the same purpose and reaches the earlier moment when the defendant has only promised the help. The two doctrines therefore line up: promising help with the purpose of advancing a crime is conspiracy, giving that help with the same purpose is complicity, and a defendant who lacks the purpose is outside both. The alignment prevents conspiracy from becoming a back door through which someone who could not be convicted as an accomplice for want of purpose is convicted for merely promising the same help.
The fact that moved the answer is whether the helper made a commitment, since the purpose and the criminal object were present in both versions. On an exam, a helper who will not perform the crime should be tested under both branches. When the helper has agreed and has the purpose, the conclusion is the same under either, and when the helper has not committed, neither branch applies.
The Purpose Requirement
The lead-in of § 5.03(1) supplies the mental state for the entire offense: a person is guilty of conspiracy only if the person acts "with the purpose of promoting or facilitating" the commission of the crime that is the object of the agreement.17 That clause comes before the colon that introduces the two alternative ways of conspiring, so it governs both of them, and an agreement that a crime will occur and an agreement to aid in its planning each depend on it.18 The common-law formula reaches a similar place by a different route. Courts that call conspiracy a specific-intent crime usually split the mental state into an intent to enter the agreement and an intent to commit, or aid in committing, the acts that make up the target crime.19 The Code's phrase supplies that second intent directly and leaves the intent to agree to the verb that describes the agreement itself. Both formulations ask what the defendant wants, and the earlier discussion of intent versus knowledge showed why wanting a crime to happen differs from merely knowing that it will.
Purpose does its most practical work in screening out routine suppliers. A telephone company that knows some of its customers use their lines to arrange drug sales does not become a party to a drug conspiracy by providing ordinary service on ordinary terms, because the prosecutor must prove that the company intended to advance the drug conspiracy through its services.20 Knowledge describes what the company expects will happen, while purpose describes what the company wants to happen. The gap matters because conspiracy punishes a plan before any harm occurs, which leaves the defendant's state of mind as the only fact separating a partner in the venture from a bystander who happens to know about it. If knowledge were enough, every business whose product could be misused would risk conspiracy liability the moment a customer's plans came to light, and the only safe course would be to investigate customers or turn them away.
The facts that moved the answer are the ones that tie the carrier's own interest to the success of the crime. A specially tailored order and a price raised to cover legal risk are the kind of circumstances that bear on whether a supplier shares the customer's aim, while a sale in the ordinary course on usual terms does not show it.21 Courts continue to treat knowing aid as insufficient. In State v. Maldonado a New Mexico appellate court found no conspiracy where the defendant sold pseudoephedrine to another person knowing it would be used to make methamphetamine, because the statute required intent rather than mere knowledge.22
The purpose must also match the crime's own conduct or result, whatever mental state the substantive offense itself demands. The Code requires purposeful behavior for conspiracy even where the target offense can be committed with a lesser state of mind: if the crime is defined by conduct, the defendant must aim to promote that conduct, and if it is defined by a result such as death, the defendant must aim to promote that result, so believing the result will follow is not enough.23 The North Dakota Supreme Court applied that logic in State v. Borner, joining a majority of jurisdictions in holding that conspiracy to commit murder requires intent to cause death and cannot rest on an extreme-indifference theory.24 The Code's drafters illustrated the point with two people who plan to destroy a building by bomb, knowing that residents will be killed: they conspire to destroy the building but not to kill the residents, because they did not want the deaths, even though a murder charge may be available if the residents die.25
Because the lead-in asks what a particular person wants, purpose is tested defendant by defendant and crime by crime. In a chain of smugglers, distributors, and retailers, the smugglers may depend on and seek to foster the retail markets, while a retailer with many suppliers may be indifferent to the success of any one source. The smugglers can then be found to have conspired to commit the retail sales while the retailer is found not to have conspired to commit the importing.26 The presence of other guilty participants never supplies one defendant's purpose.
The demand for purpose has a functional reason and a historical one. Functionally, a conspiracy charge carries disadvantages of its own for the defendant, and even those who would hold a knowing supplier liable as an accomplice to a completed crime have argued that knowing facilitation should not be enough for conspiracy.27 Requiring purpose limits that exposure to people who want the crime to occur and leaves routine dealings with wrongdoers to other offenses. Historically, when the Code's drafters first proposed reaching a person who knowingly and substantially facilitated a crime, the American Law Institute voted the proposal down and settled on the purpose of promoting or facilitating the offense, and the conspiracy lead-in uses the same words.28 A few modern codes handle knowing assistance as a separate and lesser offense of criminal facilitation instead.29
On an exam, the trap is treating knowledge of another's criminal plan as if it were purpose. State the requirement before analyzing either branch of § 5.03(1), because a defendant who lacks purpose escapes both, and look to the facts that tie the defendant's own interest to the crime's success, such as tailored service, a premium price, or a share of the proceeds.
Agreeing That a Crime Occurs
The first way the Model Penal Code defines conspiracy is by an agreement about what will happen. Subsection (1)(a) is satisfied when a defendant, acting with the purpose the lead-in requires, agrees with another person or persons that they or one or more of them will engage in conduct that constitutes the crime that is the object of the plan, or an attempt or solicitation to commit it.31 The Code keeps the core of the common law, because the agreement remains the heart of the offense, but it states what that agreement must be about with more precision than the older formula did.32 Three features of the wording carry most of the analysis: the object the parties agree on, the persons who may carry it out, and the way the whole sentence is built around the defendant's own act.
The object comes first. What the parties agree will be done must be conduct that constitutes a crime, or an attempt or solicitation to commit one, so an agreement to do something lawful falls outside this branch however secret it is and however many people join it.33 The reason lies in what conspiracy punishes. The offense reaches a plan before any harm is done, and the justification for acting so early is that the plan commits people to a course that would be criminal if carried out. An agreement whose fulfillment would be lawful threatens nothing, so early punishment would have nothing to prevent. The common law was looser about objects, as the earlier discussion of the unlawful object showed, and the Code's demand for conduct constituting a crime is part of how it narrows the offense.
The second feature is who performs the conduct. The text speaks of conduct that "they or one or more of them" will engage in, which means the defendant need not be among the people who will do the act.34 Criminal ventures divide the labor: one person enters the building, another drives, and a third pays for the equipment and stays home. If the branch required each defendant to agree to perform the conduct personally, the person who plans and finances the crime while others take the risk would escape, though that person has committed to the crime as fully as anyone. The wording instead ties the defendant to what the group agreed would happen. The branch also measures the offense by the agreement and not by the result, since it looks to conduct the parties will engage in, so the crime itself never has to occur. Whether a further overt act must be proved depends on subsection (5), which dispenses with one for conspiracies to commit first- and second-degree felonies and requires one for other crimes.35
The object also extends to an attempt or a solicitation. An attempt that fails, or a solicitation that the person asked refuses, is not the completed crime, so an agreement that someone will try to commit the crime or will ask another to commit it would not be an agreement that the crime itself will be done. Naming attempt and solicitation closes that gap. Two people who agree that one of them will pay a stranger to commit an arson have agreed to conduct, a solicitation, that is a crime in its own right, whether or not the stranger ever agrees.36
The third feature is the grammatical subject of the definition. The definition opens by declaring that "a person is guilty of conspiracy with another person or persons to commit a crime" if the person acts with the stated purpose and then does one of the listed things.37 Every clause describes the defendant's own act and the defendant's own purpose, and nothing in branch (a) says that the other party must also want the crime to occur. That omission departs from the common-law rule, taught earlier, that no conspiracy exists unless at least two people each hold the criminal purpose. The reason for the Code's choice follows from the structure of the offense. Under a two-guilty-parties rule, a defendant who proposes a robbery in complete earnest and receives apparent agreement is acquitted if the partner was secretly pretending, so liability turns on a fact the defendant neither knows nor controls. Defining the offense by what the defendant does, with the purpose the defendant has, ties liability to the defendant's own dangerous commitment.
The issue is vivid in People v. Foster. James Foster asked John Ragsdale in a bar whether he was interested in making money, and the next day described in detail a plan to rob an elderly man who kept many valuables at home. Ragsdale had not at first believed Foster was serious, and once convinced he decided to feign agreement to gather more information. Ragsdale later told the police, who met both men at the victim's residence and arrested them, and Foster was convicted of conspiracy to commit robbery.38 The appellate court reversed, reasoning that the Illinois statute required actual agreement between at least two persons and that Ragsdale, who only feigned agreement, never intended to agree.39 The State answered that it suffices if only one participant actually intends to agree, so the question for the Illinois Supreme Court was whether the 1961 amendment, which replaced "two or more persons" conspiring with "a person" who agrees with another, adopted that unilateral theory, a question on which the State relied on the similarly worded Model Penal Code and its commentary.40
The same facts yield opposite answers under the two theories, which is why the framing of the Code's definition matters. Under the bilateral theory the appellate court applied, Ragsdale's pretense means there was no meeting of minds and therefore no conspiracy. Under the unilateral theory the Code's wording points toward, Foster's own agreement, made with the purpose of promoting the robbery, may be enough, since Ragsdale's pretense takes nothing from what Foster himself did.41 How the Illinois court resolved the question, and how jurisdictions divide on it, belongs to the later reading on the plurality requirement. What this branch contributes is a text that asks about the defendant's own agreement and purpose.
On an exam, a stem that features an informant or an undercover agent who only pretends to agree is testing this point. State the common-law result first, which is no conspiracy without two guilty parties, and then note that the Code's wording, framed around what the individual defendant does, supports liability for the sincere defendant. When the stem instead features a participant who stays away from the scene, the analysis is the object-of-agreement analysis above, and the absent organizer is within the branch.
Agreeing to Aid
The Code's second route to conspiracy liability describes the helper where branch (a) describes the planner. Under subsection (1)(b), a person who acts with the purpose of promoting or facilitating a crime is guilty of conspiracy if the person "agrees to aid such other person or persons in the planning or commission of such crime or of an attempt or solicitation to commit such crime."43 The two branches often describe the same arrangement from different angles, but branch (b) states the helper's position directly: the defendant commits to assist the people who are planning or carrying out the crime. The lead-in still governs this branch, so the helper must agree with the purpose of promoting or facilitating the crime, and an agreement to help made with indifference to whether the crime succeeds falls short.44
The branch makes the agreement the culpable act, and the aid is what the agreement is about. Conspiracy is an inchoate offense, meaning one that punishes a plan before the target crime is carried out, and it is complete once the agreement is reached, even if the conspirators take no further step.45 For a helper, that means the offense is complete at the moment of commitment, whether or not the promised help is ever delivered. The Code's overt-act provision confirms how little the aid itself matters: no overt act need be proved for a conspiracy to commit a first- or second-degree felony, and for other crimes the overt act may be done by the defendant or by any person with whom the defendant conspired, so it need not be the defendant's own contribution.46 The words "planning or commission" also reach help at either stage. The person who agrees to supply the floor plan may never come near the scene, yet that agreement ties the person to the crime from the start.
Because people give help for many reasons, the branch draws its line at agreement, and the reason shows in what a conspiracy conviction brings with it. Conspiracy carries broad vicarious liability and additional punishment on top of the target crime. If every aider and abettor could be convicted of conspiracy, accomplice liability would collapse into conspiracy and every helper would face those consequences.47 Requiring an agreement keeps the offense for people who have joined a concerted plan, in which each participant has committed to the others and the group's undertaking rests partly on that commitment. A helper who acts alone has made that commitment to no one.
The same line appears in State v. Tally, which supplies real facts for the second version. Tally tried to aid men bent on a killing by preventing the delivery of a warning telegram to the victim, but there was no agreement or concert of action between him and the killers.48 Under the Code's approach, which most states have adopted, he could be convicted of aiding and abetting but not of conspiracy.49 The fact that moved the answer in both Tally and the Marsh twin is the missing understanding between helper and principals, because the help itself was real and purposeful in each.
A helper who lacks an agreement is not beyond the law's reach. Complicity offenses punish support and encouragement given to another person's crime, and the Code's accomplice rules, like its conspiracy offense, demand the purpose of promoting or facilitating that crime.50 The two bodies of law therefore share the demand for purpose, and what separates them is the agreement. Marsh in the second version may be an accomplice if the burglary occurs, but Marsh is not a conspirator.
On an exam, the trap is treating aid without agreement as conspiracy, which happens whenever a stem shows a helper with real purpose and real assistance but never shows the helper and the principals reaching an understanding. Because aid so often looks like agreement on the page, the branch is best run by testing the agreement before the help.