Can a defendant withdraw from the commission of a crime?

before it is committed." (People v. Fiu (2008) 165 Cal.App.4th 360, 384.) "To be entitled to an instruction on the withdrawal defense, a defendant charged with aiding and abetting a crime must produce substantial evidence showing that (1) he notified the other principals known to him of his intention to withdraw from the commission of the intended crime or crimes, and (2) he did everything in his power to prevent the crime or crimes from being committed. [Citations.]" (People v. Shelmire (2005) 130 Cal.App.4th 1044, 1055.)