Noah Webster
Legal
LE'GAL, adjective [Latin legalis, from lex, legis, law.]
1. According to law; in conformity with law; as a legal standard or test; a legal procedure.
2. Lawful; permitted by law; as a legal trade. Anything is legal which the laws do not forbid.
3. According to the law of works, as distinguished from free grace; or resting on works for salvation.
4. Pertaining to law; created by law.
The exception must be confined to legal crimes.
So we use the phrase, criminal law.