South Korea ? North Korea announced today it will free a “repentant” American missionary detained on Christmas for illegally crossing the border from China.

Robert Park of Tucson, Ariz., slipped across the frozen Tumen River into the North carrying letters calling on North Korean leader Kim Jong Il to close the country’s notoriously brutal prison camps and to step down from power, rights activists in Seoul said.

North Korean media reported in a brief dispatch Dec. 29 that authorities had detained an American suspected of illegal entry but said nothing more until today, leaving his fate in question for weeks.