Cal. Welf. and Inst. Code § 225
In each county there shall be a juvenile justice commission consisting of not less than 7 and no more than 15 citizens. Two or more of the members shall be persons who are between 14 and 21 years of age, provided there are available persons between 14 and 21 years of age who are able to carry out the duties of a commission member in a manner satisfactory to the appointing authority. Each person serving as a member of a probation committee immediately prior to September 15, 1961, shall be a member of the juvenile justice commission and shall continue to serve as such until such time as his or her term of appointment as a member of the probation committee would have expired under any prior provision of law. Upon a vacancy occurring in the membership of the commission and upon the expiration of the term of office of any member, a successor shall be appointed by the presiding judge of the superior court with the concurrence of the judge of the juvenile court or, in a county having more than one judge of the juvenile court, with the concurrence of the presiding judge of the juvenile court for a term of four years. When a vacancy occurs for any reason other than the expiration of a term of office, the appointee to fill such vacancy shall hold office for the unexpired term of his or her predecessor.
Appointments may be made by the presiding judge of the superior court, in the same manner designated in this section for the filling of vacancies, to increase the membership of a commission to the maximum of 15 in any county which has a commission with a membership of less than 15 members.
In any county in which the membership of the commission, on the effective date of amendments to this section enacted at the 1971 Regular Session of the Legislature, exceeds the maximum number permitted by this section, no additional appointments shall be made until the number of commissioners is less than the maximum number permitted by this section. In any case, such county's commission membership shall, on or after January 1, 1974, be no greater than the maximum permitted by this section.
Ca. Welf. and Inst. Code § 225