Deuteronomy 21:6-9

6and all the elders of that city nearest the corpse must wash their hands over the heifer whose neck was broken in the valley.

7Then they must proclaim, “Our hands have not spilled this blood, nor have we witnessed the crime.

8Do not blame your people Israel whom you redeemed, O Lord, and do not hold them accountable for the bloodshed of an innocent person.” Then atonement will be made for the bloodshed.

9In this manner you will purge out the guilt of innocent blood from among you, for you must do what is right before the Lord.