Deuteronomy 19:13

9 and if you carefully keep all these commandments I am giving you today, loving the LORD your God and walking in His ways at all times, then you are to add three more cities to these three.

10 Thus innocent blood will not be shed in the land that the LORD your God is giving you as an inheritance, so that you will not be guilty of bloodshed.

11 If, however, a man hates his neighbor and lies in wait, attacks him and kills him, and then flees to one of these cities,

12 the elders of his city must send for him, bring him back, and hand him over to the avenger of blood to die.

13 You must show him no pity. You are to purge from Israel the guilt of shedding innocent blood, that it may go well with you.

14 You must not move your neighbor’s boundary marker, which was set up by your ancestors to mark the inheritance you shall receive in the land that the LORD your God is giving you to possess.

15 A lone witness is not sufficient to establish any wrongdoing or sin against a man, regardless of what offense he may have committed. A matter must be established by the testimony of two or three witnesses.

16 If a false witness testifies against someone, accusing him of a crime,

17 both parties to the dispute must stand in the presence of the LORD, before the priests and judges who are in office at that time.

Read all of Deuteronomy 19