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 Wisconsin, criminal conspiracy is addressed under state statutes, specifically under Chapter 939 of the Wisconsin Statutes. According to Wisconsin law, a criminal conspiracy occurs when two or more persons agree to commit a crime and at least one of them performs an overt act in furtherance of the conspiracy. The state recognizes the seriousness of collaborative efforts to commit crimes and provides for the prosecution of individuals involved in the planning stages of criminal activity, even if they do not participate in the execution of the crime itself. Penalties for conspiracy in Wisconsin vary depending on the nature of the crime that was the object of the conspiracy, with the potential for significant fines and imprisonment. This is in line with federal law, such as 18 U.S.C. §371, which also criminalizes conspiracy to commit an offense against the United States or to defraud the United States, with penalties including fines and imprisonment for up to five years. Both state and federal laws reflect the dual aims of disrupting the collaborative power of conspirators and enabling the prosecution of those involved in the planning of a crime.