Malum in se

malum in se (mal-uhm in say) adv. Latin referring to an act that is "wrong in itself," in its very nature being illegal because it violates the natural, moral or public principles of a civilized society. In criminal law it is one of the collection of crimes which are traditional and not just created by statute, which are "malum prohibitum." Example: murder, rape, burglary, and robbery are malum in se, while violations of the Securities and Exchange Act or most "white collar crimes" are malum prohibitum. (See: malum prohibitum)

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MALUM IN SE. Evil in itself.
     2. An offence malum in se is one which is naturally evil, as murder, theft, and the like; offences at common law are generally mala in sese.
     3. An offence malum prohibitum, on the contrary, is not naturally an evil, but becomes so in consequence of its being forbidden; as playing at games, which being innocent before, have become unlawful in consequence of being forbidden. Vide Bac. Ab. Assumpsit, A, note; 2 Rolle's Ab. 355.