Deuteronomy 17:2-7

2If a man or woman among you in one of the towns that the LORD your God gives you is found doing evil in the sight of the LORD your God by transgressing His covenant 3and going to worship other gods, bowing down to them or to the sun or moon or any of the host of heaven—which I have forbidden— 4and if it is reported and you hear about it, you must investigate it thoroughly.

If the report is true and such an abomination has happened in Israel, 5you must bring out to your gates the man or woman who has done this evil thing, and you must stone that person to death. 6On the testimony of two or three witnesses a man shall be put to death, but he shall not be executed on the testimony of a lone witness. 7The hands of the witnesses shall be the first in putting him to death, and after that, the hands of all the people. So you must purge the evil from among you.1