Whenever the venue is changed in any criminal case or in any civil action or proceeding in which his county or the state is interested or a party, it shall be the duty of the state's attorney of the county where such criminal case was commenced, or of the county interested in such civil action or proceeding, to appear and prosecute such criminal case and to prosecute or defend such civil action or proceeding in the county to which the same may be changed.
SDCL 7-16-15