Introduction

Plurality and the Bilateral Rule

Introduction

Conspiracy is a crime about partnership. At common law it is an agreement between two or more persons to commit an unlawful act, or to commit a lawful act by unlawful means, and the offense is complete when the agreement is made, whether or not the planned crime is ever carried out.¹ That is why conspiracy is called an inchoate crime, meaning one that punishes conduct aimed at a criminal objective without waiting for the objective to be reached. It reaches further back into the planning stage than attempt does, and the usual justification is that an agreement makes the intent less equivocal: one person's private resolve may never go anywhere, but two people who have committed themselves to each other are more likely to see the plan through.² As with other crimes, conspiracy requires an act and a mental state, and here the agreement is the act while the intent to achieve the unlawful objective is the mental state.³

Treating the agreement as the act explains why the number of participants matters so much. A plot kept inside one person's head is only an intention, and the criminal law does not punish intention standing alone; the agreement is what carries the intention outward into a shared undertaking, and that shared undertaking is the act.⁴ Courts accordingly call the agreement the essence or gist of the crime, and they look to its nature to decide whether the required mental state and the required plurality are both present.⁵ The same idea appears at the origin of the offense: in the Poulterers' Case in 1611, the court treated the confederating together of the conspirators, rather than the false indictment they planned, as the gist of the wrong.⁶ The agreement need not be written or spoken, since a tacit understanding inferred from the circumstances will do, but it must still be an agreement, and an agreement requires someone on the other end.⁷ A person cannot conspire with himself, so the first analytical step in any conspiracy problem is to count the participants whose minds genuinely join the plan.

Jurisdictions answer the counting question in two different ways. The traditional common-law answer is that at least two persons must be actually committed to the plan, each genuinely intending the unlawful objective. Under that rule, if one of the two merely pretends to agree, as an undercover officer or informant typically does, courts have traditionally held that no conspiracy exists, even though the other party fully intended the crime.⁸ The Model Penal Code, in § 5.03(1), takes a unilateral approach that looks to the defendant's own agreement and purpose, and most modern recodifications follow it, so the same facts can support a conviction in one jurisdiction and fail in another.⁹ This chapter begins with the common-law count, because its rules explain both the traditional results and the reforms that replaced them. The first rule to learn is that conspiracy requires two persons who each genuinely share the criminal objective.