S.D. Codified Laws § 60-8-8
The state's attorney of each county shall prosecute any person violating any of the provisions of §§ 60-8-3 to 60-8-6, inclusive, in that county. The state's attorney shall enforce these sections. If the state's attorney has any information or knowledge or has any reason to believe that any of the provisions of these sections are being violated in the county, the state's attorney shall investigate and use every legitimate means to secure the necessary and proper evidence of the violation. Immediately upon securing the evidence, the state's attorney shall file a complaint or preliminary information against any person against whom the state's attorney has any evidence of any such violation. The state's attorney shall have the person arrested and shall vigorously prosecute such charges to final judgment.
SDCL 60-8-8