Deuteronomy 21:4
And the elders of that city shall bring down the heifer unto a rough valley, which is neither eared nor sown, and shall strike off the heifer’s neck there in the valley: And the elders of that city shall bring down the heifer unto a rough valley, which is neither eared nor sown, and shall strike off the heifer’s neck there in the valley:
When a slain person was found and the killer was not known, the elders of the city nearest to the place were to take a heifer that had never been worked and lead it down to a rough valley that had never been plowed or planted. There in that uncultivated valley they were to break the heifer's neck in a solemn and public ceremony. The rite was appointed to compel the rulers to declare openly their abhorrence of murder. It was also to impress upon them their duty to search diligently for the criminal and bring him to justice. They were not to treat such a crime with indifference or carelessness, nor were they to shelter the guilty from punishment, for failure to act made them partakers in the evil and left guilt and defilement resting upon the land and its people.