An agreement by two or more people to commit an illegal act or to commit a legal act using illegal means. Proving conspiracy requires evidence that the parties agreed to the plan before taking action. Proving criminal conspiracy usually requires evidence that some overt action occurred in furtherance of the plan. Some conspiracies may give rise to both criminal and civil charges. For example, a scheme by a group of salesmen to sell used automobiles as new, could be the basis for two actions: criminal prosecution for fraud and conspiracy; and a civil action by victims of the scheme for damages for the fraud and conspiracy.