Deuteronomy 13:12-15

12You may hear that the residents in one of the cities which the Lord your God is giving you to live in

13have been led away from the Lord your God by worthless people. You may hear that these people have been saying, “Let’s worship other gods.” (Those gods may be gods you’ve never heard of.)

14Then make a thorough investigation. If it is true, and you can prove that this disgusting thing has been done among you,

15you must kill the residents of that city with swords and destroy that city and everyone in it, including the animals, because they are claimed by God.