New York Consolidated Laws, Penal Law - PEN § 105.30 Conspiracy;  no defense

It is no defense to a prosecution for conspiracy that, owing to criminal irresponsibility or other legal incapacity or exemption, or to unawareness of the criminal nature of the agreement or the object conduct or of the defendant's criminal purpose or to other factors precluding the mental state required for the commission of conspiracy or the object crime, one or more of the defendant's co-conspirators could not be guilty of conspiracy or the object crime.