Introduction

The Overt Act Requirement

Introduction

Conspiracy is an agreement between two or more people to commit an unlawful act. The agreement itself is the actus reus (the physical element the prosecution must prove), and the intent to carry out the unlawful object supplies the mens rea.¹ Because it is an inchoate offense, one punished before the target crime is carried out, conspiracy reaches further back into the planning stage than attempt does.² That placement raises a puzzle. Two people can agree to commit a crime and then do nothing else, and the question is whether the offense is already complete at the moment of agreement or whether something further must happen first.

Two authorities mark the poles of the lesson. At common law, a conspiracy became complete as soon as the parties reached an agreement with the requisite criminal intent, and the doctrine demanded no overt act in furtherance of that agreement.³ An overt act is a step beyond the agreement that advances the plan, so under the common-law rule the two parties above have already committed the crime without taking one. Model Penal Code § 5.03(5) takes a different position for most offenses: no one may be convicted of conspiracy to commit a crime other than a felony of the first or second degree unless an overt act in pursuance of the conspiracy is alleged and proved, whether done by the defendant or by a person with whom the defendant conspired.⁴ Punishing the agreement alone is justified on the theory that an agreement makes the intent to commit the crime less equivocal and makes it more likely that the crime will actually be committed.⁵ A requirement of an overt act supplies outward evidence that the agreement was more than talk, which is why many modern jurisdictions add it.

Because the overt act is an add-on to the agreement that varies from one jurisdiction to another, the first job on any conspiracy fact pattern is to identify which regime governs: the common-law rule, a statute that requires an act, or the Model Penal Code's split. This chapter follows that order. It begins with the common-law baseline, turns to the statutes that add an act, then takes up what counts as an overt act and whose act counts, and finally examines the Model Penal Code, which sorts conspiracies by the seriousness of the object crime. The place to start is the baseline itself: what does it mean for conspiracy to be complete at the moment of agreement?