Concept
Events After the Agreement
Factual Impossibility
Events After the Agreement
The rule that opened this chapter holds that a conspirator cannot defend by showing that outside facts made the ultimate objective impossible to reach, because the agreement and the intent to commit the unlawful act remain sufficient to establish guilt.1 That holding rests on a point about timing. A conspiracy consists of the agreement and the intent behind it, together with an overt act in the jurisdictions that require one, and the earlier discussion of why impossibility fails explained that the agreement is the gist of the offense. Once those elements are present the crime exists, and nothing in its definition asks whether the objective is later reached. Events that follow can change what the conspirators are able to do, but they cannot reach back and remove an element that has already been satisfied.
Two related rules apply the same reasoning to different kinds of later events. Government interdiction covers the case in which law enforcement frustrates the objective, for example by seizing the contraband the conspirators meant to sell, and the conspirators gain no immunity from that frustration. Withdrawal covers the case in which a participant has a change of heart after the agreement, and at common law that change is generally no defense to the conspiracy itself. Withdrawal receives full treatment elsewhere, so it appears here only to show the pattern. One event comes from outside the group and the other from inside it, yet each arrives after the offense is complete, and so each leaves the offense in place.
The incentives behind the pattern show why the law could not safely read it any other way. If a seizure ended the conspiracy, the effectiveness of the police would decide whether the group could be punished at all, and the more promptly officers stopped the plan, the less liability the conspirators would bear. If a change of heart erased the offense, every participant caught after the group had formed would have a reason to claim that the commitment had lapsed, and the danger the group had already created, as a standing combination able to turn to further crimes, would go unpunished. Treating the offense as complete at the agreement removes both temptations, because liability then depends on what the parties did and intended when they combined, and not on what happened to the plan afterward.
The two versions differ only in when the outside event occurred, and the answer does not change. In the first version the claim is the familiar one that the objective could not be achieved, which the common-law rule rejects.2 In the second version the conspiracy was already complete when the shipment moved, so the later event had nothing left to undo. The timing of the frustrating fact therefore does not drive the result. What would change the result is a fact that goes to an element at the moment of agreement, such as one partner being an undercover officer who only pretended to join, or one partner honestly believing the owner had consented to the taking. Those facts leave the agreement or the intent unproved, as the preceding sub-sections showed, and that is a failure of an element rather than a later frustration of a completed offense. Students lose this issue when they treat a frustrated objective as an ended conspiracy and then hunt for a defense the doctrine never offered.
The next two sub-sections take the examples in turn, beginning with government interdiction.
Government Interdiction
Government interdiction is the most natural form of the argument that the objective has slipped out of reach after the agreement. Agents seize the contraband, the intended buyer is arrested, or the shipment is turned back at the border, and the defendants then say that the purpose of their plan has been defeated, so the conspiracy is over and nothing remains to punish. That argument asks the court to adopt an automatic termination rule, under which a conspiracy ends the moment its objective is defeated. In United States v. Jimenez Recio the Supreme Court held that conspiracy contains no "automatic termination" rule, so a government success in ending the conspiracy's objective gives the conspirators no immunity from prosecution.4
The reason follows from where the offense is complete. A conspiracy is established by the agreement and the intent behind it, plus an overt act in jurisdictions that require one, and whether the objective is ever reached is not among the elements.5 An event that frustrates the objective therefore comes after the crime already exists. To say that such an event terminates the conspiracy, a court would have to make the offense depend on a fact that its definition never mentions. The same logic governs a closely related event: if two people agree to kill a third and the intended victim dies of natural causes soon afterward, the pair can be convicted of conspiracy to murder even if they take no further step once they learn of the death.6 Interdiction belongs to the same family. Each is an outside event that leaves the objective unattainable, and none of them removes an element that has already been satisfied.
The seizure does not help them. The agreement and intent were complete before the police acted, and the police success is just another later event. The incentive reasoning supports that result. If a seizure ended the conspiracy, liability would turn on how quickly law enforcement happened to act, and a group stopped early would escape punishment while an undetected one would not, even though both created the same danger when they combined. A rule with that effect would reward the conspirators for being caught early, so the law treats the offense as already complete.
Interdiction shares a link with impossibility but is not identical to it. Impossibility ordinarily involves facts that already stood in the way when the parties agreed, while interdiction is a later act by the government. Both leave the objective unattainable, and the rule rejecting an impossibility defense and the rule refusing automatic termination reach the same answer for the same reason.7
The rule has a limit that comes from the element it does not touch. Rejecting automatic termination protects the prosecution only when there was a conspiracy to begin with. If the agreement was to do something that is neither a crime nor an unlawful act, the elements of conspiracy were never met, and the government's later conduct neither creates nor cures that gap.8
The charge fails, and the reason is not what the government did. The object of the agreement was lawful, so there was never a conspiracy for the interdiction rule to preserve. Change one fact and the answer reverses: if the shipment had been contraband, the same customs hold would have left the owners fully liable. The object of the agreement when it was made decides the case, and the later government action decides nothing in either version. Students lose this issue when they argue that the government's own success excuses an agreement to commit a crime, or, in the opposite direction, when they assume that interdiction can supply a criminal object the agreement never had.
Withdrawal Distinguished
Withdrawal is the second application of the rule that events after the agreement leave the offense in place. It differs from interdiction in where the event originates, because the change comes from inside the group. A participant who has agreed and then has a change of heart is asking the court to treat the conspiracy as though that participant had never been part of it. The traditional answer is that withdrawal after the conspiracy has formed gives the withdrawing member no defense to the conspiracy charge itself.10 The rule is strict because the crime is complete with the agreement, so no later action can exonerate the conspirator of that offense.11 Attempt law reasons the same way: once the actors have crossed the threshold of criminality, they cannot go back, and the common law applies that idea to refuse abandonment as a defense to conspiracy.12
Jurisdictions that add an overt act requirement by statute move the moment of completion, and the withdrawal rule moves with it. In those jurisdictions a defendant who withdraws before any overt act has been committed is not punishable as a member of the conspiracy, yet as a practical matter this differs little from the common-law rule.13 The exception fits the timing principle that governs this whole part of the chapter. Before the overt act the offense is still incomplete, so the withdrawal arrives before the crime exists and not after it.
Denying withdrawal as a defense to the conspiracy does not make the withdrawing member answerable for everything the others later do. A conspirator who withdraws effectively may limit liability for later crimes committed by the remaining members. Courts ask for an affirmative act that brings the withdrawal home to the confederates, made in time for them to abandon the plan and communicated in a way that would inform a reasonable person, and the notice is insufficient unless it reaches all of the other conspirators.14 Each requirement has a function. Notice has to reach everyone because any member left uninformed continues to act on the assumption that the withdrawing member is still committed. It has to come in time because an announcement made after the plan can no longer be called off gives the others no real chance to abandon it. A private change of mind gives them nothing to act on at all, so silent resolve limits no one's liability.
The Model Penal Code is more generous. It recognizes withdrawal as an affirmative defense to a conspiracy charge, but only when the defendant has thwarted the success of the conspiracy under circumstances manifesting a complete and voluntary renunciation of the criminal purpose.15 A member who informs the police in time to stop the plan is the clearest example of thwarting. Two premises support that structure. The first is that the act of agreement alone is not dangerous enough to warrant punishment despite a later renunciation, which departs from the common-law view, developed earlier in this chapter, that a combination is dangerous from the moment it forms. The second is that thwarting must be required, because the objective of a conspiracy will generally be pursued by the remaining members despite one member's renunciation, so a change of heart that leaves the plan running removes none of the danger.16 A member who only walks away, or who only warns the others and lets the plan go forward, has therefore thwarted nothing, and the defense remains unavailable even though the notice may still limit liability for later crimes.17
Set beside impossibility, mistake, and feigned agreement, withdrawal attacks a different point. Those arguments contest whether the objective was reachable or whether an element existed at the moment of agreement. Withdrawal concedes that every element was met and asks only what effect the defendant's later conduct should have. The common-law answer is that the later act leaves the conspiracy charge intact and operates, at most, on liability for the other members' later crimes. The Code's answer is that a later act which thwarts the plan can excuse the conspiracy itself. The trap is treating a change of heart as an escape from the conspiracy charge in a jurisdiction that has not adopted the Code's thwarting defense. The dedicated reading on withdrawal develops the notice requirement, the effect on liability for crimes committed after the withdrawal, and the Code defense in full.