Both Herod and Pontios Pilate (Hērōidēs te kai Pontius Peilatos). Luke alone (Luk 23:12) tells of the reconciliation between Herod and Pilate at the trial of Jesus. So Peter and the rest interpret this prophecy as directly fulfilled in their conduct towards Jesus Christ.
Whom thou didst anoint (hon echrisas). As in Act 4:26(cf. Luk 4:18; Isa 61:1). Inaugurated as King Messiah.