Mo. Rev. Stat. § 547.230: State may sue out writ of error.

The prosecuting attorney may apply for and prosecute a writ of error in the supreme court, in like manner and with like effect as such writ may be prosecuted by the defendant; but in such case the defendant shall not be required to enter into any recognizance to answer further to such offense, but if the judgment of the circuit court shall be reversed, the defendant may be arrested on warrant and brought before the circuit court for judgment, or such other proceedings as the case may require.