People v. Stallworth (2008) 164 Cal. App. 4th 1079, concluded that CC 401 is neither confusing nor incomplete provided that CC 220 is also given so that the jury understands that the reasonable doubt standard applies to an aider and abettor’s knowledge.
However, the defense should have the right to an instruction pinpointing its theory that the required knowledge element was not proved beyond a reasonable doubt. (See Forecite PG ***)