Can a defendant be held liable as an aider and abettor of a crime?

commission of a crime, . . . whether they directly commit the act constituting the offense, or aid and abet in its commission. . . .' (See . . . 971 ['all persons concerned in the commission of a crime, who by the operation of other provisions of this code are principals therein, shall hereafter be prosecuted, tried and punished as principals. . . .'].)" (People v. Calhoun (2007) 40 Cal.4th 398, 402.)

A defendant can be liable as an aider and abettor in two ways. "First, an aider and abettor with the necessary mental state is guilty of the intended crime. Second, under the natural and probable consequences doctrine, an aider and abettor is guilty not only of the intended crime, but also 'for any other offense that was a "natural and probable consequence" of the crime aided and abetted.' [Citation.]" (People v. McCoy (2001) 25 Cal.4th 1111, 1117.)