Deuteronomy 21:1-9

Unsolved homicides

1 If a corpse is found on the ground the LORD your God is giving you to possess, lying in a field, and the identity of the killer is unknown,
2 your elders and judges must come out and measure the distances to the cities nearest the body.
3 Once it is determined which city is closest to the dead body, its elders must take a young cow that hasn't been used or yet pulled a plow,
4 and those elders will take the cow down to a ravine with a flowing stream—one that has not been plowed or planted—and they will break the cow's neck right there in the river valley.
5 Then the priests, the descendants of Levi, will step forward because the LORD your God selected them to minister for him and to bless in the LORD's name, and because every legal dispute and case of assault is decided by them.
6 All the elders of the city closest to the corpse will wash their hands over the cow whose neck was broken in the river valley.
7 They will then solemnly state: "Our hands did not shed this blood. Our eyes did not see it happen.
8 LORD, please forgive your people Israel, whom you saved. Don't put the guilt of innocent bloodshed on your people Israel." Then the bloodguilt will be forgiven them.
9 But you must remove innocent bloodshed from your community; do only what is right in the LORD's eyes.