Deuteronomy 17:2-5

A man or woman in one of the towns the LORD gave you might be found doing something evil and breaking the Agreement. That person may have served other gods and bowed down to them or to the sun or moon or stars of the sky, which I have commanded should not be done. If someone has told you about it, you must look into the matter carefully. If it is true that such a hateful thing has happened in Israel, take the man or woman who has done the evil thing to the city gates and throw stones at that person until he dies.