Deuteronomy 19:10-13
10 In this way, innocent blood will not be shed, and you will not become guilty of bloodshed in the land the Lord your God is giving you as an inheritance.(A)
11 But if someone hates his neighbor, lies in ambush for him, attacks him, and strikes him fatally, and flees to one of these cities,
12 the elders of his city must send for him, take him from there, and hand him over to the avenger of blood and he will die.
13 You must not look on him with pity but purge from Israel the guilt of shedding innocent blood, and you will prosper.