Deuteronomy 21:6-8

And all the elders of that city nearest to the slain man shall wash their hands over the heifer whose neck was broken in the valley, and they shall testify, ‘Our hands did not shed this blood, nor did our eyes see it shed. Accept atonement, O LORD, for your people Israel, whom you have redeemed, and do not set the guilt of innocent blood in the midst of your people Israel, so that their blood guilt be atoned for.’