Deuteronomy 17:2-7

17:2 Suppose a man or woman is discovered among you – in one of your villages that the Lord your God is giving you – who sins before the Lord your God and breaks his covenant 17:3 by serving other gods and worshiping them – the sun, moon, or any other heavenly bodies which I have not permitted you to worship. 17:4 When it is reported to you and you hear about it, you must investigate carefully. If it is indeed true that such a disgraceful thing is being done in Israel, 17:5 you must bring to your city gates that man or woman who has done this wicked thing – that very man or woman – and you must stone that person to death. 17:6 At the testimony of two or three witnesses they must be executed. They cannot be put to death on the testimony of only one witness. 17:7 The witnesses must be first to begin the execution, and then all the people are to join in afterward. In this way you will purge evil from among you.

Deuteronomy 17:9

17:9 You will go to the Levitical priests and the judge in office in those days and seek a solution; they will render a verdict.