What is the test for establishing that there was a conspiracy between a party and a party?

Once the existence of the conspiracy has been independently established, the offering party must then make three additional showings in order for the content of the coconspirator's statement to be considered by the trier of fact. That party must show: (1) that the declarant (who may or may not be the defendant) was participating in a conspiracy at the time of the declaration; (2) that the declaration was made in furtherance of the objective of the conspiracy; and (3) that at the time of the declaration the party against whom the evidence is offered was participating, or would later participate, in the conspiracy. (People v. Sanders, supra, 11 Cal.4th at p. 516; People v. Hardy, supra, 2 Cal.4th at p. 139; accord, Evid. Code, 1223.)