Gov. Code, § 31787.65

(a) For purposes of Section 31787, the final compensation upon which the special death benefit is calculated for the eligible surviving spouse or eligible children of a safety member killed in the performance of his or her duty shall be increased at any time the increase is effective and to the extent the compensation is increased for then-active members employed in the job classification and membership category that was applicable to the deceased member at the time of the injury, or the onset of the disease, causing death. The deceased member’s final compensation shall be deemed to be subject to further increases hereunder only until the earlier of (1) the death of the surviving spouse or eligible children or (2) the date that the deceased member would have attained the age of 50 years.

(b) This section applies only to a county of the seventh class, as defined by Sections 28020 and 28028, as amended by Chapter 1204 of the Statutes of 1971, and shall not be operative until the board of supervisors, by resolution, makes this section applicable in the county. A resolution to make this section operative in the county shall specify whether these provisions apply retroactively or prospectively only.