CA Gov't Code Section 8639

The qualifications of each standby officer should be carefully investigated, and the governing body may request the Director of Emergency Services to aid in the investigation of any prospective appointee. No examination or investigation shall be made without the consent of the prospective appointee.

Consideration shall be given to places of residence and work, so that for each office for which standby officers are appointed there shall be the greatest probability of survivorship. Standby officers may be residents or officers of a political subdivision other than that to which they are appointed as standby officers.