1.  Service before becoming member.  A member who served as a full-time law enforcement officer with a federal, state, county or local law enforcement agency before becoming a member is entitled under this subsection to purchase service credit for the period of time that the member served as a law enforcement officer if the member has at least 15 years of creditable service at the time of retirement by complying with the terms and conditions of this subsection and the applicable provisions of subsection 2. Service credit purchased under this section is limited to 4 years. Notwithstanding anything to the contrary, a member for which service credit under this section is to be granted must provide a certified statement from the appropriate retirement system that the service credit to be granted has not been and will not be used to obtain other retirement benefits.  

2.  Members qualified for credit at actuarial cost.  A member qualified under subsection 1 to purchase service credit at the cost set forth in this subsection is entitled to service credit if the member pays an amount that, together with regular interest on that amount, is the actuarial equivalent, at the effective date of the retirement benefit, of the portion of the retirement benefit based on the additional creditable service.