California Code, Penal Code - PEN § 190.25

(a) The penalty for a defendant found guilty of murder in the first degree shall be confinement in state prison for a term of life without the possibility of parole in any case in which any of the following special circumstances has been charged and specially found under Section 190.4, to be true:  the victim was the operator or driver of a bus, taxicab, streetcar, cable car, trackless trolley, or other motor vehicle operated on land, including a vehicle operated on stationary rails or on a track or rail suspended in the air, used for the transportation of persons for hire, or the victim was a station agent or ticket agent for the entity providing such transportation, who, while engaged in the course of the performance of his or her duties was intentionally killed, and such defendant knew or reasonably should have known that such victim was the operator or driver of a bus, taxicab, streetcar, cable car, trackless trolley, or other motor vehicle operated on land, including a vehicle operated on stationary rails or on a track or rail suspended in the air, used for the transportation of persons for hire, or was a station agent or ticket agent for the entity providing such transportation, engaged in the performance of his or her duties.

(b) Every person whether or not the actual killer found guilty of intentionally aiding, abetting, counseling, commanding, inducing, soliciting, requesting, or assisting any actor in the commission of murder in the first degree shall suffer confinement in state prison for a term of life without the possibility of parole, in any case in which one or more of the special circumstances enumerated in subdivision (a) of this section has been charged and specially found under Section 190.4 to be true.

(c) Nothing in this section shall be construed to prohibit the charging or finding of any special circumstance pursuant to Sections 190.1, 190.2, 190.3, 190.4, and 190.5.