What is the effect of section 654 of the California Criminal Code on a defendant who has committed multiple offences in the same criminal offence?

Section 654 reads in relevant part: "An act or omission that is punishable in different ways by different provisions of law shall be punished under the provision that provides for the longest potential term of imprisonment, but in no case shall the act or omission be punished under more than one provision." ( 654, subd. (a).) The purpose of section 654 is to assure a defendant's punishment is commensurate with his culpability. (People v. Perez (1979) 23 Cal.3d 545, 550-551.)

"[S]ection 654 applies not only where there was but one act in the ordinary sense, but also where there was a course of conduct which violated more than one statute but nevertheless constituted an indivisible transaction." (People v. Perez, supra, 23 Cal.3d at p. 551.) On the other hand, "if the evidence discloses that a defendant entertained multiple criminal objectives which were independent of and not merely incidental to each other, the trial court may impose punishment for independent violations committed in pursuit of each objective even though the violations shared common acts or were parts of an otherwise indivisible course of conduct." (People v. Liu (1996) 46 Cal.App.4th 1119, 1135.)