c. 1400, "sinful, wicked;" mid-15c., "of or pertaining to a legally punishable offense, of the nature of a crime;" late 15c., "guilty of crime," from Old French criminel, criminal "criminal, despicable, wicked" (11c.) and directly from Late Latin criminalis "pertaining to crime," from Latin crimen (genitive criminis); see crime. It preserves the Latin -n-. Other adjectives include criminous (mid-15c.), criminative. Criminal law (or criminal justice) has been distinguished from civil in English at least since late 15c.
"person who has committed a punishable offense against public law," 1620s, from criminal (adj.). Particularly, "person convicted of a crime by proof or confession."