Deuteronomy 17:2-7, 9

“If there is found among you, within any of your towns that the LORD your God is giving you, a man or woman who does what is evil in the sight of the LORD your God, in transgressing his covenant, and has gone and served other gods and worshiped them, or the sun or the moon or any of the host of heaven, which I have forbidden, and it is told you and you hear of it, then you shall inquire diligently, and if it is true and certain that such an abomination has been done in Israel, then you shall bring out to your gates that man or woman who has done this evil thing, and you shall stone that man or woman to death with stones. On the evidence of two witnesses or of three witnesses the one who is to die shall be put to death; a person shall not be put to death on the evidence of one witness. The hand of the witnesses shall be first against him to put him to death, and afterward the hand of all the people. So you shall purge the evil from your midst.

And you shall come to the Levitical priests and to the judge who is in office in those days, and you shall consult them, and they shall declare to you the decision.