The principle of law that says that an out-of-court confession, unsupported by other facts, is insufficient to support a criminal confession is the __ rule.

Answer: Corpus Delecti Rule

Explanation:

Corpus Delecti Rule is the regulation that describes that any illegally authorized confession or confession made outside of court cannot be considered as the evidence.

This rule in usually followed in criminal cases and related investigation. In this case, an official confession or actual evidence is required for proving occurrence of crime or supporting the confession against convict.