(1) If a dual member dies in service in any system, the member's service in all systems may be combined for the sole purpose of determining the surviving spouse's eligibility to receive a death benefit from each of the member's current and prior systems.

(2) Each system shall use its own criteria to:

(a) Determine the surviving spouse's eligibility for a death benefit; and

(b) Calculate the death benefit based on service actually established in that system.

(3) The surviving spouse shall receive the same benefit from each system that would have been received if the member were active in the system at the time of death. The spouse shall be allowed to substitute the member's base salary from any system as the compensation used in calculating the allowance.

(4) This section shall not apply to the Washington state patrol retirement system established under chapter 43.43 RCW.