4. Investigatory records.

Investigative reports are closed records until the investigation becomes "inactive." Mo.Rev.Stat. §  610.100.2. The term "inactive" is defined to include a decision by a law enforcement agency not to pursue a case, the expiration of the applicable statute of limitations, or the finality of convictions and exhaustion of all appeals. Mo.Rev.Stat. §  610.100.1(3).