Mo. Rev. Stat. § 66.200

The official responsible for law enforcement in any municipality in a first class county having a charter form of government shall cause an exact copy of all the police records of the municipality pertaining to all violations constituting felonies or misdemeanors punishable by a jail sentence except traffic violations which arose after January 1, 1960, to be delivered to the official or agency responsible for law enforcement in the unincorporated areas of the county within six months after October 13, 1963. After copies of all existing police records have been delivered to the county officer or agency, exact copies of subsequent municipal police records pertaining to such violations shall be transmitted to the county authority immediately after the information is obtained by the municipal police and all records of the county agency shall be available to the municipal police. Final disposition of the violations shall be transmitted to the county agency.