What is the test for an accomplice in a murder case?

mental state must be at least that required of the direct perpetrator. 'To prove that a defendant is an accomplice . . . the prosecution must show that the defendant acted "with knowledge of the criminal purpose of the perpetrator and with an intent or purpose either of committing, or of encouraging or facilitating commission of, the offense." ([People v. Beeman (1984) 35 Cal.3d 547,] 560, italics in original.) When the offense charged is a specific intent crime, the accomplice must "share the specific intent of the perpetrator"; this occurs when the accomplice "knows the full extent of the perpetrator's criminal purpose and gives aid or encouragement with the intent or purpose of facilitating the perpetrator's commission of the crime." (Ibid.)' (People v. Prettyman, supra, 14 Cal.4th at p. 259.) What this means here, when the charged offense and the intended offense murder or attempted murderare the same, i.e., when guilt does not depend on the natural and probable consequences doctrine, is that the aider and abettor must know and share the murderous intent of the actual perpetrator." (McCoy, supra, 25 Cal.4th at p. 1118, fn. omitted.)