"It is better for you that one man should die for the people, not that the whole nation should perish."
From the blood of Abel, an innocent man assassinated by his own brother, humanity has been plagued with murders. According to Moses' instruction, a murder has to be atoned, and the only thing that atones it, is the blood of the person who shed it. It is not because of virtue awarded to vengeance, but because shed blood defiles the Land of Israel. The Torah even commands that the city living closest to a slain body takes vicarious responsibity for an unsolved murder (Deuteronomy 21:1-9; Numbers 35:33-34).
When arriving in Canaan, the Children of Israel were to cleanse the land by ridding it of all the people who practiced idolatrous murders. Israel failed to obey that command which later became a snare to them. God then cleansed the Land by sending Judah to temporary exile not once but twice. We are now coming to the end of the second exile and an inhabited Israel probably has again unsolved murders on its hands. I do not know if religious authorities in Israel regularly clean the Land from unsolved murder, but we know that at Yom Kippur atonement is made on a national level.
The Torah tells us that in the case of an unsolved murder, someone needs to take the responsibility. The Torahs suggest the ciy closest to the found corpse. We are taught an absolution ceremony which involves the decapitation of an heifer, its blood poured in a river, and city official washing their hands off the responsibility of the murder in the presence of priests. The Levites were to attend the ceremony because God had chosen them not only as religious, but also as judicial authorities (Deuteronomy 21:5). Justice is a religious matter, not civil, so in the Torah system, the priests are the religious and judicial authority. The role of the king is actually to enforce the rulings of the priests and of the Torah so you might say that in 'God's world' the administrative, judicial, and legislative branches of government come under the dictates of the Torah: a religious document.
What I find amazing is that in a world where both innocent and guilty always try to claim their innocence, God teaches us the virtue of endorsing the guilt of a non-committed crime for the benefit of all.
When Yeshua came, He taught that anger and character assassination were the seed of murder (Matthew 5:21-22), but He also Himself assumed responsibility for every unsolved murder in the world which makes us, humanity, responsible for His death, which He Himself atones for as Caiaphas made allusion to (John 11:49-50), and .the Talmud declares in, "The death of a righteous man atones for the sinner".
May we always remember Yeshua who, though He did not sin, took responsibility for all our heinous murders to cleanse the Land with His own innocent shed blood that we may drink of the River of Life.