Deuteronomy 21:6-8

All the elders of that city which is nearest to the slain man shall wash their hands over the heifer whose neck was broken in the valley; and they shall answer and say, ‘Our hands did not shed this blood, nor did our eyes see it. Forgive Your people Israel whom You have redeemed, O LORD, and do not place the guilt of innocent blood in the midst of Your people Israel.’ And the bloodguiltiness shall be forgiven them.