Deuteronomy 17:2-7

²"If there is found among you, within any of your towns which the LORD your God gives you, a man or woman who does what is evil in the sight of the LORD your God, in transgressing his covenant, ³and 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, ⁴and it is told you and you hear of it; then you shall inquire diligently, and if it is true and certain that such an abominable thing has been done in Israel, ⁵then you shall bring forth 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. ⁶On the evidence of two witnesses or of three witnesses he that is to die shall be put to death; a person shall not be put to death on the evidence of one witness. ⁷The 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 the midst of you.