The Expansion of the Principle of Legality in the Criminal Code as a Renewal of Criminal Law

The principle of legality is a very fundamental principle in criminal law. The principle of legality contained in Article 1 paragraph (1) of the Criminal Code absolutely adheres to the principle that no act can be punished without a prior statutory provision that sets out a clear formulation of the act. There are quite a number of acts that according to the public's view are disgraceful and deserve punishment (customary offences), but law enforcers cannot follow up on them because they collide with the principle of formal legality. This study aims to find out and analyze the extension of the principle of legality as a reform in criminal law, this study uses a normative juridical approach, based on the results of the study it was concluded that the expansion of the legality principle from formal to material in criminal law reform in Indonesia was motivated by the manifestation of the motivation in reforming the Criminal Code since the Dutch government with criminal sanctions that were more in line with the noble concepts of the Indonesian nation. The principle of material legality will no longer be opposed to the principle of formal legality, but will complement each other in order to achieve legal interests, namely certainty, usability, and legal justice