In the United States, the modern laws related to criminal conspiracy began to take shape in the late nineteenth century. In the most basic definition, conspiracy is an agreement between two or more persons formed for the purpose of committing a crime. The purpose behind criminalizing conspiracy was twofold: to exercise some control over “inchoate” (i.e., unripe or incomplete) activities, and to punish group behavior that had crime as its object.
The crime of conspiracy is the illegitimate agreement. Although simple to define, the offense presents many difficult problems in further analysis. What is an “agreement”? At what point does it begin? What happens if there are multiple agreements over time, or if a person withdraws from the agreement?
Since the essence of the crime of conspiracy is the agreement, the prosecution must first show that an agreement existed to commit a crime. Direct proof of a formal agreement is not necessary; the existence of an agreement may be shown by drawing reasonable inferences from the conduct of the actors or other circumstantial evidence. A common course of conduct, aiding and abetting, collusive actions, or other types of circumstantial evidence may suffice, if it is convincing enough.
Conspiracy charges are seen most often in federal court, rather than in state court. The greater resources available to federal law enforcement agencies for complex investigations with surveillance, wiretapping, and confidential informants may be one of the reasons for this.
In some situations, no overt act need be taken by the conspirators once the agreement is made. In other words, criminal liability may attach upon the formation of the agreement. To avoid complicity in a conspiracy, some courts have held that “one must withdraw before any overt act is taken in furtherance of the agreement.” See, e.g., U.S. v. Karr, 742 F.2d 493, 497 (9th Cir. 1984). As a further example, one court held that “For drug conspiracies under 21 U.S.C. Sect. 846, no overt act is required. Once the agreement is made, the offense is complete.” U.S. v. Francis, 916 F.2d 464, 466 (8th Cir. 1990). Once the conspiracy has formed, a conspirator may withdraw from it, but may still be faced with a conspiracy charge, and for any acts in furtherance of the conspiracy before his withdrawal.
To withdraw from the conspiracy, a person must show that he or she deliberately acted to disavow the purpose of the conspiracy. A defendant must take timely action, and give notice to his co-conspirators that his participation is finished.
One of the main issues in conspiracy cases is the “overt act” requirement. In most conspiracy scenarios, the prosecution must show that one of the conspirators took some step in furtherance of the conspiracy. The step need not be hugely significant, and it need not be unlawful in itself.
Generally, any step in preparation will suffice. Any act taken by any conspirator will normally be used against all the defendants. However, some courts have held that if the overt act(s) were performed by defendants who were ultimately acquitted of conspiracy charges, then those overt acts may not be used against other defendants. U.S. v. Hutchinson, 488 F.2d 484 (8th Cir. 1973).
Generally, the prosecution must show that the conspirators specifically intended both to agree, and to commit, the object offense. Mere association with a conspirator is not enough: there must be an intent to agree. Some uncertainty can arise when the defendants have no knowledge of the illegal nature of the conspiracy’s goal.
This so-called “corrupt motives” doctrine has been resolved in various ways by state and federal courts. In general, at the federal level, knowledge of the federal nature of the crime (interstate commerce, assault on a federal officer, etc.) need not be shown in a conspiracy prosecution except where the substantive crime requires such proof.
The so-called “Wharton’s Rule” prohibits the prosecution of both the conspiracy and the principal offense when both charges involve the same activity. In recent years, this rule has been somewhat restricted. The rule does not apply when the principle offense has not been completed. The Supreme Court case of Ianelli v. U.S., 420 U.S. 770 (1975) stands for the idea that there is a judicial presumption that dual prosecution for the two offenses is not allowed.
What is important is to examine the nature of the relationships between the parties in such cases. “Wheel” conspiracies involve one central person who makes arrangements with different persons, who form the “spokes” of the wheel. “Chain” conspiracies involve various persons who are linked by some unity of purpose in the illegal goal. Conspiracy law is vast and complex, and became more so with the advent of the RICO statute (18 U.S.C. Sect. 1961-1968). Entire criminal “enterprises” could be pursued, based on predicate crimes.
Prosecutors may attempt to improperly join multiple defendants in the same indictment, so as to “taint” some by association with others. Defendants may be joined together if they participate in the same transaction. The key question in joinder is whether there has been prejudice to the defendant. Severance—that is, separating one or more defendants from others in an indictment—is at the discretion of the trial judge. Key considerations that courts will weigh are: the “spill-over” effect of evidence among joint defendants, conflicts between defendants, and the possibility of antagonistic defenses among defendants.
Conspiracy cases present many challenges for the defense. They require an awareness of investigative methods and a nuanced understanding of the factual details of a case. At the early stages of a case, attacking an indictment based on misjoinder, improper venue, multiplicity, or various other legal bases can force the prosecution to narrow its allegations. Intense scrutiny can then be applied to the following key legal or factual issues: the alleged “agreement” and “overt act(s)”, the defendant’s state of mind, the merger of the conspiracy and the substantive offense (a favorite prosecution tactic), double jeopardy issues, the duration of the conspiracy, severance, peremptory challenges, and any co-conspirator declarations. Indeed, the very fact that conspiracy cases are complicated presents many opportunities for an aggressive defense.