Deuteronomy 19:13-18
English Standard Version
15"A single witness shall not suffice against a person for any crime or for any wrong in connection with any offense that he has committed. Only on the evidence of two witnesses or of three witnesses shall a charge be established.
16If a malicious witness arises to accuse a person of wrongdoing,
17then both parties to the dispute shall appear before the Lord, before the priests and the judges who are in office in those days.
18The judges shall inquire diligently, and if the witness is a false witness and has accused his brother falsely,