What is the test for a jury trial where a defendant is found liable as an aider and abettor?

In a jury trial, "when the prosecution relies on the 'natural and probable consequences' doctrine to hold a defendant liable as an aider and abettor, the trial court must, on its own initiative, identify and describe for the jury any target offense allegedly aided and abetted by the defendant." (People v. Prettyman (1996) 14 Cal.4th 248, 268.) The purpose of this requirement is to ensure that the jury does not convict the defendant "based on the jury's generalized belief that the defendant intended to assist and/or encourage unspecified 'nefarious' conduct." (Ibid.) The defendant must intend to aid and abet the commission of a criminal act. (Ibid.)

Page 15