Mo. Rev. Stat. § 86.140
The deductions provided for herein shall be made notwithstanding that the minimum compensation provided by law for any member shall be reduced thereby. Every member shall be deemed to consent to the deductions made and provided for herein, and shall receipt for his full salary or compensation and payment of salary or compensation less said deduction shall be a full and complete discharge and acquittance of all claims and demands whatsoever for services rendered during the period covered by the payment except as to benefits provided by sections 86.010 to 86.193. The board of police commissioners shall certify to the board of trustees on each and every payroll or in such other manner as the board of trustees shall prescribe the amount deducted, and such amounts shall be paid into said annuity savings fund and shall be credited together with regular interest thereon to the individual account of the member from whose compensation said deduction was made.
§ 86.140, RSMo