In what circumstances will a jury be instructed on the penalty of first degree murder?

In People v. Deacon, 117 Cal.App.2d 206, 255 P.2d 98, the jury was instructed on first degree murder and the penalty therefor, but was also instructed in effect that if the defendant was guilty of murder, it was only murder in the second degree. The appellate court held that the defendant suffered no prejudice from the giving of the instructions on first degree murder, commenting (117 Cal.App.2d at page 210, 255 P.2d at page 101): 'If it was surplusage (and admittedly the instruction on the penalty for first-degree murder is such) it cannot be complained of as prejudicial, for appellant was, after all, convicted of second-degree murder, not first.'