Deuteronomy 21:6-9

6And all the elders of that city 1which is nearest to the person killed shall 2wash their hands over the heifer whose neck was broken in the valley; 7and they shall respond and say, ‘Our hands did not shed this blood, nor did our eyes see who did. 83Forgive Your people Israel whom You have redeemed, Lord, and do not place the guilt for 4innocent blood in the midst of Your people Israel.’ And the guilt for bloodshed shall be 5forgiven them. 96So you shall remove the guilt for innocent blood from your midst, when you do what is right in the eyes of the Lord.