Mo. Rev. Stat. § 109.190
In all cases where the public or any person interested has a right to inspect or take extracts or make copies from any public records, instruments or documents, any person has the right of access to the records, documents or instruments for the purpose of making photographs of them while in the possession, custody and control of the lawful custodian thereof or his authorized deputy. The work shall be done under the supervision of the lawful custodian of the records who may adopt and enforce reasonable rules governing the work. The work shall, where possible, be done in the room where the records, documents or instruments are by law kept, but if that is impossible or impracticable, the work shall be done in another room or place as nearly adjacent to the place of custody as possible to be determined by the custodian of the records. While the work authorized herein is in progress, the lawful custodian of the records may charge the person desiring to make the photographs a reasonable rate for his services or for the services of a deputy to supervise the work and for the use of the room or place where the work is done.
§ 109.190, RSMo