Legal Literacy- This article discusses the importance of legal principles and the principle of legality in the Indonesian legal system, especially in the implementation of criminal law. The author explains in detail the laws and regulations that form the basis for law enforcement agencies in carrying out their functions, duties, authorities and responsibilities in implementing the principle of the rule of law. In addition, the author also discusses the legal principles that serve as boundaries in providing legal certainty.

Law enforcement (law enforcement) is one of the characteristics that reflects that Indonesia is a state based on law (Article 1 Paragraph 3 of the 1945 Constitution) in order to guarantee the supremacy of law for the administration of the state through statutory regulations as a basis for law enforcement agencies in carrying out their functions, duties, authorities and responsibilities in implementing the principle of the rule of law (rechtsstaat).

One form of implementation of applicable substantive law is the existence of formal law administration instruments. In the context of criminal law, in general, criminal justice proceedings are carried out based on Law Number 8 of 1981 concerning the Criminal Procedure Code (KUHAP) as the parent source of criminal justice procedural law in Indonesia.

Basically, criminal procedure law or criminal law formal…