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 Indiana, criminal conspiracy is defined under Indiana Code IC 35-41-5-2. It occurs when a person agrees with another individual to commit a felony and performs an overt act in furtherance of the agreement. The intent to commit the felony is a crucial element of the crime. The penalties for conspiracy in Indiana depend on the underlying felony that the conspirators agreed to commit. If the conspiracy was to commit a crime that is a Level 2 felony, the conspiracy charge itself is a Level 3 felony, and so on, with the conspiracy charge being one level lower than the intended crime, except for murder conspiracies, which are treated as Level 2 felonies. Federal law, specifically 18 U.S.C. § 371, also prohibits criminal conspiracies, targeting agreements to commit any offense against the United States or to defraud the United States or its agencies. Under federal law, individuals involved in a conspiracy can face fines and imprisonment for up to five years. Both state and federal statutes aim to dismantle the collaborative efforts to commit crimes and allow for the prosecution of those involved in the planning stages, even if they do not participate in the execution of the crime itself.