Manila - The principal suspect in the grisly killing of at least 57 people in the southern Philippines surrendered Thursday to a senior aide of President Gloria Macapagal Arroyo. Datu Andal Ampatuan Junior was turned over by members of his family, close allies of Arroyo, to presidential aide Jesus Dureza in Shariff Aguak town in Maguindanao province, 930 kilometres south of Manila.