Deut 17:5-7

5then you shall bring out to your gates that man or that woman who has committed this crime and you shall stone the man or woman to death.6On the evidence of two or three witnesses the death sentence shall be executed; a person must not be put to death on the evidence of only one witness.7The hands of the witnesses shall be the first raised against the person to execute the death penalty, and afterward the hands of all the people. So you shall purge the evil from your midst.