A criminal conspiracy is generally a partnership formed to commit a crime or crimes. A criminal conspiracy exists when two or more persons form an agreement to violate a law that includes criminal penalties, and then take one or more steps designed to accomplish the goal of the conspiracy.

Federal and state statutes make criminal conspiracies illegal for two primary purposes: (1) to help combat the powerful forces created when two or more people collaborate to commit a crime; and (2) to allow criminal prosecutors (state and federal) to prosecute persons who play a role in planning a crime but who are not involved in the physical acts taken to complete the underlying crime.

For example, under federal law, if two or more persons conspire either to commit any offense against the United States, or to defraud the United States, or any agency of the United States in any manner or for any purpose, and one or more of such persons do any act to accomplish the objective of the conspiracy, each of the conspirators may be fined under and imprisoned for up to five years. See 18 U.S.C. §371. And most states have statutes (usually located in the penal or criminal code) that make criminal conspiracies a crime and include significant punishment upon conviction.

In Pennsylvania, criminal conspiracy is defined under Title 18, Section 903 of the Pennsylvania Consolidated Statutes. A person is guilty of conspiracy with another person or persons to commit a crime if, with the intent of promoting or facilitating its commission, they agree to engage in conduct that constitutes such crime or an attempt or solicitation to commit such crime. The state does not require that an overt act be taken in furtherance of the conspiracy for a conviction, except in the case of conspiracy to commit a first or second-degree felony. The penalties for conspiracy in Pennsylvania are generally the same as for the underlying offense that was the object of the conspiracy. This aligns with the dual purposes of conspiracy statutes: to dismantle the collaborative efforts to commit crimes and to hold accountable those involved in the planning stages of criminal activities. At the federal level, as per 18 U.S.C. § 371, a conspiracy to commit any offense against the United States or to defraud the United States carries a penalty of fines and imprisonment for up to five years, provided an overt act in furtherance of the conspiracy has been committed by at least one conspirator.