One of the fundamental purposes of the criminal law is to prevent conduct that is harmful to society. Accordingly, the law punishes conduct that threatens to produce the harm, as well as conduct that has actually produced it. However, the law does not punish all persons shown to harbor a criminal intent. Everyone occasionally thinks of committing a crime, but few actually carry the thought into action. Therefore, the law proceeds only against persons who engage in acts that sufficiently demonstrate their firm intention to commit a crime.
The act of conspiracy. The rationale of conspiracy is that the required objective manifestation of disposition to criminality is provided by the act of agreement. Agreement represents an advancement of the intentions that a person conceives in his mind. Intervention of the law at this point is said to be justified because the act of agreement indicates a firm intention to promote the crime, and because the agreement enhances the likelihood that unlawful action will ensue. The greater probability of action is believed to stem from the dynamics of group activity: the group exerts psychological pressure against withdrawal of its members, a single individual cannot deflect the will of the group as easily as he can change his own mind, and the group can bring greater resources to bear on its objective than could an individual acting alone. Conspiracy law, then, seeks to counter the special dangers incident to group activity reaching back to incipient stages of criminal behavior.
Ironically, conspiracy was initially directed neither at preparatory activity nor at group crime in general. Rather, it was a narrowly circumscribed statutory remedy designed to combat abuses against the administration of justice. According to Edward Coke, it consisted of "a consultation and agreement between two or more to appeal or indict an innocent man falsely and maliciously of felony, whom accordingly they cause to be indicted and appealed; and afterward the party is lawfully acquitted" (p. 142). A writ of conspiracy would lie only for this particular offense, and only when the offense (including acquittal of the falsely indicted party) had actually taken place. However in 1611 the Court of Star Chamber extended the law by upholding a conspiracy conviction even though the rarely accused party was not indicted (Poulterers' Case, 77 Eng. Rep. 813 (K.B. 1611) (Coke)). The court reasoned that the confederating together, and not the false indictment, was the gist of the offense. The ramifications of this decision were twofold. First, if it was not necessary that the intended injury occur, then conspiracy punished the attempted crime. Second, if the agreement and not the false indictment was the target of conspiracy law, then conspiracy was loosed from its mooring: subsequent decisions logically could and in fact did hold that agreement to commit any unlawful act was criminal conspiracy.
There is a serious question as to whether the act of agreement is not too slender a reed to support such a vast extension of conspiracy law. First, agreement—a "conscious union of wills upon a common undertaking" (Developments in the Law, p. 926)—is an act primarily mental in nature. This is emphasized by the fact that parties to an agreement need not communicate directly; a tacit understanding may constitute an agreement. Conspiracy thus comes perilously close to criminalizing an evil state of mind without any accompanying act. Most jurisdictions have therefore bolstered the act element by requiring an overt act in pursuance of the conspiracy. The function of the overt act is "to manifest that the conspiracy is at work . . . and is neither a project still resting solely in the minds of the conspirators nor a fully completed operation no longer in existence" (Yates v. United States, 354 U.S. 298, 334 (1957)). However, this requirement rarely hinders a conspiracy prosecution because almost any act, however trivial, will suffice. For example, if two persons plan to rob a bank, the purchase of disguises would be a sufficient overt act. An act of this nature is highly equivocal; it would not support an attempt conviction because it is not a substantial act that sufficiently demonstrates the defendants firm intention to rob the bank. There is reason, then, to support the position of a few states that set a stricter standard by requiring a substantial step in pursuance of the object of the conspiracy, and thereby render conspiracy more comparable to the law of attempt (Note, pp. 1153–1154).
Second, conspiracy is a clandestine activity. Persons generally do not form illegal covenants openly. In the interests of security, a person may carry out his part of a conspiracy without even being informed of the identity of his coconspirators. Since an agreement of this kind can rarely be shown by direct proof, it must be inferred from circumstantial evidence of cooperation between the defendants. What people do is, of course, evidence of what lies in their minds. Since a person's acts might, by extension of this principle, create an inference concerning what he has agreed to do, it is fair to infer an agreement to join a conspiracy from the performance of acts that further its purpose. However, this evidentiary rule can obscure the basic principle that conspiracy is not established without proof of an agreement. Conspiracy is not merely a concurrence of wills, but a concurrence resulting from agreement. Even if a conspiracy between two parties is established, not every act of a third party that assists in accomplishment of the objective of the conspiracy is a sufficient basis to demonstrate his concurrence in that agreement.
Unfortunately, many courts have not adhered strictly to the requirement of an agreement. The decision of the United States Supreme Court in Interstate Circuit Inc. v. United States, 306 U.S. 208 (1939) is more representative of the courts' loose treatment of the requirement of an actual agreement. In this case, the manager of Interstate, a motion picture exhibitor that dominated the motion picture business in certain cities in Texas, sent a letter to eight motion picture distributors demanding certain concessions as conditions for continued exhibition of those distributors' films. He requested that, in selling their products to "subsequent run" theaters, the distributors impose the restrictions that the films never be exhibited below a certain admission price or in conjunction with another film as a double feature. Both of these restrictions constituted significant departures from prior practice.
The Court found that the distributors conspired with one another and with Interstate to impose the demanded restrictions in violation of the Sherman Antitrust Act. Agreement among the distributors was inferred from several strands of evidence. First, the letter named all eight distributors as addressees; hence each distributor was aware that the proposals were being considered by the others. Second, the distributors were in active competition; hence without unanimous action with respect to the restrictions, each risked substantial loss of business, and, conversely, unanimity yielded a prospect of increased profits. Finally, the distributors did in fact act with substantial unanimity. However, since the actions of each distributor might just as easily have resulted from the exercise of self-interest in the absence of any illegal agreement, the Court had to take one step further. It declared, "We think that in the circumstances of this case such agreement for the imposition of the restrictions upon subsequent run exhibitors was not a prerequisite to an unlawful conspiracy. It was enough that, knowing that concerted action was contemplated and invited, the distributors gave their adherence to the scheme and participated in it" (Interstate Circuit Inc., 226). Such a dilution of the requirement of agreement may be necessary in view of the special problems of enforcing the nation's antitrust policy. However, difficulties of proof lead courts to extend the principle to conspiracy prosecutions generally.
The scope of a conspiracy. Another large problem that arises in connection with the requirement of an agreement is that of determining the scope of a conspiracy—who are the parties and what are their objectives. The determination is critical, since it defines the potential liability of each defendant. Ascertaining the boundaries or scope of a conspiratorial relationship is crucial for resolving several major questions. Among these are (1) the propriety of joint prosecution; (2) the admissibility against a defendant of hearsay declarations of other conspirators; (3) the satisfaction of the overt-act requirement; (4) the liability of a defendant for substantive crimes committed by other conspirators pursuant to a conspiracy; and (5) the possibility of multiple convictions for conspiracy and substantive crimes.
The problems generated by the question of the scope of conspiracy are among the most troublesome in conspiracy law. They derive from the necessity of applying the theoretical idea of agreement to the reality of ongoing, fluctuating partnerships engaged in diverse criminal activity. Can a single agreement embrace persons unknown to one another in a sprawling, far-flung illegal operation? Can separate decisions made over a course of time to commit various crimes be said to stem from a single agreement? Generally, does the multiplicity of relationships making up a criminal organization constitute one large conspiracy or several smaller ones?
The law has developed several different models with which to approach the question of scope. One such model is that of a chain, where each party performs a role that aids succeeding parties in accomplishing the criminal objectives of the conspiracy. An illustration of such a single conspiracy, its parts bound together as links in a chain, is the process of distributing an illegal foreign drug. In one such case, smugglers, middlemen, and retailers were convicted of a single conspiracy to smuggle and distribute narcotics (United States v. Bruno, 105 F.2d 921 (2d Cir.), rev'd on other grounds, 308 U.S. 287 (1939)). On appeal, the defendants argued that there were separate conspiracies—one between the smugglers and the middlemen, and the other between the middlemen and the retailers. The court rejected this view and found a single overall conspiracy despite the absence of cooperation or communication between the smugglers and retailers, stating:
The smugglers knew that the middlemen must sell to retailers; and the retailers knew that the middlemen must buy of importers of one sort or another. Thus the conspirators at one end of the chain knew that the unlawful business would not, and could not, stop with their buyers; and those at the other end knew that it had not begun with their sellers. . . . The accused were embarked upon a venture, in all parts of which each was a participant, and an abettor in the sense that the success of the part with which he was immediately concerned, was dependent upon the success of the whole .
Another prototype, denominated the wheel conspiracy, exists where one central figure, the hub, conspires with several others, the spokes. The question is whether there is a rim to bind all the spokes together in a single conspiracy. A rim is found only when there is proof that the spokes were aware of one another's existence and that all promoted the furtherance of some single illegal objective. In the celebrated case of Kotteakos v. United States, 328 U.S. 750 (1946), one man, Brown, agreed with a number of different persons to obtain loans for each of them from the Federal Housing Authority through fraudulent means. Since each of these transactions was entirely distinct and independent of the others, there could not be a finding of a single conspiracy. Instead, there were a number of separate conspiracies consisting of Brown and each of his customers.
On the other hand, a single conspiracy may be found where each person's success depends on continued operation of the hub, which in turn depends on success of all the spokes. In this situation each spoke can be said to contribute to the separate objectives of all the other spokes. In the case of Anderson v. Superior Court, 78 Cal. App. 2d 22, 177 P.2d 315 (1947), a woman who referred pregnant women to a physician for abortions was indicted for a conspiracy to commit abortion with him and with other persons who referred pregnant women to him. She was also indicted for the illegal abortions committed upon the women she referred, as well as for the abortions committed upon women referred by the other persons who had made such referrals. The court held that the evidence permitted the inference of a conspiracy among all the referring persons and the physician, because the defendant knew that the others were referring business to him, and because his continued functioning and hence the woman's commission depended upon continuance of all these sources of referral. For these reasons it might be said that she contributed to each separate instance of abortion.
These models deal with situations in which various parties conspire to promote a single unlawful objective. The traditional concept of agreement can also accommodate the situation where a well-defined group conspires to commit multiple crimes; so long as all these crimes are the objects of "the same agreement or continuous conspiratorial relationship," a finding of one large conspiracy is appropriate (Model Penal Code, 1962, § 5.03(c)).
However, traditional conspiracy law is inadequate when applied to criminal organizations in which highly diverse objectives are pursued by apparently unrelated individuals. Hence, Congress enacted the Racketeer Influenced and Corrupt Organizations Act of 1970 [RICO] to cope with the growing problem of organized crime (18 U.S.C. §§ 1961–1968 (1999)). This act facilitates conspiracy prosecutions by modifying the traditional idea of a conspiratorial objective. Instead of proving that each defendant conspired to commit a particular crime or crimes—a task that is exceedingly difficult in the context of a large, sprawling criminal organization—the prosecution need only show that each defendant conspired to promote the enterprise through his individual pattern of criminal activity. No matter how diverse the goals of a large criminal organization, there is but one objective: to promote the furtherance of the enterprise.
The problem with this tendency to view conspiracy as an ongoing criminal enterprise is that it beclouds the idea of an act of agreement. Many persons may thereby be snared in the coils of a single conspiracy whose nature and membership were unknown to them. The effect may be to convict people in circumstances where the traditional requirement of personal guilt is not present. The Model Penal Code has attempted to reformulate the definition of conspiracy to avoid this consequence. For each defendant, it would ask whether and with whom he agreed to commit which parts of the entire illegal scheme, thus reaffirming the centrality of the agreement in a conspiracy prosecution (MPC, 1960, commentary on § 5.03). A number of state criminal codes have now adopted this approach.