What is the test for proving a conspiracy?

Conspirators are vicariously liable for the unintended acts of coconspirators if such acts are in furtherance of the conspiracy. Coconspirators are liable for any reasonably foreseeable offenses committed by the perpetrator. (People v. Hardy (1992) 2 Cal.4th 86, 188.) Proof of a conspiracy serves to impose criminal liability on all conspirators for the crimes committed in furtherance of the conspiracy. Where several parties conspire or combine together to commit any unlawful act, each is criminally responsible for the acts of his or her confederates committed in furtherance of the common design for which they combine. (People v. Superior Court (Shamis) (1997) 58 Cal.App.4th 833, 842-843.)

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