In New York, Conspiracy requires: 1) an agreement (between at least two people), 2) intent to enter the agreement and 3) intent to achieve a common objective. Under the New York State Penal Law, renunciation by a co-conspirator must involve a complete change of the defendant’s mind, (not simply a change of circumstances that increased the defendant’s chance of being caught or made it more difficult for him to complete the crime).
Out-of-court statements (either written or oral) made by co-conspirators, which are made during and in furtherance of the conspiracy, are admissible against all co-conspirators. Hence, it is irrelevant which co-conspirator made the statement.
In New York, the co-conspirator must effectively announce to all accomplices that he has changed his mind in time for them to effectively abandon the crime. In order not to be found guilty of the crime of Conspiracy, the alleged co-conspirator must actually have prevented the crime from occurring (either by notifying the victim or the police). Accordingly, for the crimes of Solicitation, Attempt or Conspiracy, a co-conspirator must 1) announce his intent to withdraw from the conspiracy, 2) actually withdraw from the conspiracy and 3) thwart the crime from occurring.