Crimes committed may fall under certain categories, the intent of the offender being the primary consideration.
There is a distinction between crimes which are mala in se or wrongful from their nature, such as murder, homicide, rape and the like, and those that are regarded as mala prohibitum, or wrong merely because prohibited by statute.
According to the Bouvierâ€™s Law Dictionary, crimes mala in se are those so serious in their effects on society as to call for almost unanimous condemnation of its members; while crimes mala prohibita are violations of mere rules of convenience designed to secure a more orderly regulation of the affairs of society.
There are certain criteria which will help one to distinguish whether a crime committed is a mala prohibitum or mala in se.
First, as to nature. Mala in se is punishable because of their very wrongful nature of the offense, that is to say, the act or omission offends not only the law but also the sense of universal morality and so offensive as to call for the State for its punishment. These include the crimes which society in general condemns their commission. Mala prohibitum, on the other hand, is wrong because the law prohibits it. A special law enjoining its commission provides for it.
Second, as to use of good faith as a defense. In crimes mala in se, good faith may be used as a valid defense, unless the crimes is the result of culpa. Good faith in crimes mala prohibitum is not a defense.
Third, as to use of intent as an element of the crime. In mala in se, intent is an element; in mala prohibitum, it is not.
Fourth, in offenses mala in se, the degree of accomplishment of the crimes is taken into account in punishing the offender; in mala prohibitum, the act gives rise to a crime only when it is consummated.
These are just some of the basic distinctions which qualify whether an offense is a mala in se or mala prohibitum.