Upon the death of an active or retired member, the Oklahoma Police Pension and Retirement System shall pay to the beneficiary of the member under paragraph 13 of Section 50-101 of this title or if there is no such beneficiary or if such beneficiary predeceases the member, to the member's estate or, if properly designated by the member, to a trust, the sum of Four Thousand Dollars ($4,000.00) as a death benefit for those active or retired members who died prior to July 1, 1999. For those active or retired members who die on or after July 1, 1999, the sum shall be Five Thousand Dollars ($5,000.00).