(1) Upon completion of twenty years of such service and upon retirement, each such member shall receive a pension which, together with an annuity for such years of service as provided in paragraph four of this subdivision, shall be sufficient to provide him with a retirement allowance of one-half of his final average salary.

(2) Upon completion of more than twenty years of such service and upon retirement, each such member shall receive, for each year of service in excess of twenty, an additional pension which, together with an annuity for each such year as provided in paragraph four of this subdivision, shall be equal to one-sixtieth of his final average salary, provided, however, that the pension payable pursuant to this section shall not exceed three-quarters of final average salary.

(3) Upon attainment of the mandatory retirement age without completion of twenty years of such service, each such member shall receive a pension which, together with an annuity for such years of service as provided in paragraph four of this subdivision, shall be equal to one-fortieth of his final average salary for each year of creditable service in such division. Every such member shall also be entitled to an additional pension equal to the pension for any creditable service rendered while not an employee of the division as provided under paragraphs three and four of subdivision a of section three hundred seventy-five of this article. This latter pension shall not increase the total allowance to more than one-half of his final average salary.

(4) The annuity provided under paragraphs one, two and three of this subdivision shall be the actuarial equivalent, at the time of retirement, of the member's accumulated contributions based upon the rate of contribution fixed under the provisions of subdivision c of section three hundred eighty-one-a of this article and upon the salaries earned while in such service rendered after April sixteenth, nineteen hundred thirty-eight and prior to April first, nineteen hundred sixty. Such annuity shall be computed as it would be if it were not reduced by the actuarial equivalent of any outstanding loan nor by reason of the member's election to decrease his contributions toward retirement in order to apply the resulting amount toward payment of contributions for old age and survivor's insurance. Any accumulated contributions in excess of the amount required to provide the annuity computed pursuant to this paragraph shall be used to increase the member's retirement allowance.

(5) Notwithstanding the provisions of this subdivision, members transferred to the division of state police pursuant to a chapter of the laws of nineteen hundred ninety-seven, upon retirement shall receive either the allowances provided by this subdivision or those provided under the retirement system to which they participated prior to such transfer whichever allowance shall be the higher. c. Credit for previous police service. (1) Police service. In computing the years of total creditable service in such division, full credit shall be given and full allowance shall be made for service rendered as a police officer or member of a police force or department of a state park authority or commission or an organized police force or department of a county, city, town, village, police district, authority or other participating employer or member of the capital police force in the office of general services while a member of the New York state and local police and fire retirement system, of the New York state and local employees' retirement system or of the New York city police pension fund and for all service for which full credit has been given and full allowance made pursuant to the provisions of section three hundred seventy-five-h of this chapter provided, however, that full credit pursuant to the provisions of such section shall mean only such service as would be creditable service pursuant to the provisions of section three hundred eighty-three or section three hundred eighty-three-a or three hundred eighty-three-b enacted by chapter six hundred seventy-seven of the laws of nineteen hundred eighty-six of this chapter or pursuant to the provisions of title thirteen of the administrative code of the city of New York for any member contributing pursuant to this section who transferred to the division of state police.

(2) State university police officer service. Upon completion of more than twenty years of service, and upon retirement, each such member who was previously credited with service credit in the New York state and local employees' retirement system or the New York state and local police and fire retirement system as an officer appointed by the state university pursuant to paragraph l of subdivision two of section three hundred fifty-five of the education law and who has successfully completed a course of law enforcement training as provided in such section of the education law or for any such officer who retires on and after January first, two thousand eighteen who has successfully completed such course of law enforcement training within two years of his or her date of appointment shall receive for each such year of previous service, up to a total of no greater than five years of previous service, additional service credit equal to one-sixtieth of his or her final average salary. d. Retirement for cause. Upon receipt of a certificate of the superintendent of state police, pursuant to section two hundred twenty-nine of the executive law, a member who has accrued twenty-five or more years of service credit under this section shall be retired on the first day of the second month next succeeding the date such certificate was filed with the comptroller. e. Mandatory retirement. A member subject to the provisions of this section shall be retired on December thirty-first of the year in which he or she attains sixty years of age. Notwithstanding the foregoing, any member in service in the division on August fifteenth, two thousand seven, and who on that date was entitled to receive retirement benefits on the thirty-first day of December in the year in which he or she attained fifty-seven years of age as provided in paragraph three of subdivision b of this section, may elect to retain such entitlement, provided the member remains in service on the thirtieth day of December in the year in which he or she attains fifty-seven years of age. The provisions of this subdivision shall not apply to the superintendent. f. Credit for military service. In computing the years of total creditable service in the division of state police full credit shall be given and full allowance shall be made for service of such member in war after world war I as defined in section three hundred two of this article, provided such member at the time of his entrance into the armed forces was in police service as defined in subdivision eleven of section three hundred two of this article. g. Transfer of membership to employees' retirement system. Any member currently enrolled pursuant to this section and who previously transferred service credit from the New York state and local employees' retirement system to the New York state and local police and fire retirement system, may elect to transfer such previously transferred service credit back to the New York state and local employees' retirement system, and such member shall have the option to retroactively transfer his or her membership into such employees' retirement system.