roya fanaei

In today's law schools, the nullum crimen, nulla poena sine lege principle and the codification of the list of crimes and punishments are, without any doubt, considered the doctrine of legal scholars. However, with the exponential increase in the number and quality of new crimes and the absence of their criminalization, the question arises as to whether the lack of a codified criminal law for such crimes will prevent judicial action and the issuance of an appropriate sentence. This paper has been written with the aim of reviewing the concept of the nullum crimen, nulla poena sine lege principle in order to adopt appropriate criminal measures against emerging crimes, by examining the Usuli and jurisprudential arguments and by descriptive method and analysis of documents. Findings of the research show that, when criminalizing, it is necessary for the legislator, through a new reading of the above said principle, instead of “exhaustive explanation of criminal instances”, while providing a comprehensive definition of crime by setting a specific criterion to distinguish the crimes, leave it to the judge to determine the criminal instances. Since in the case of emerging crimes, even in the absence of criminal law, jurists and Usulis believe that ruling on the permissibility of such doubted issues should be avoided, the legislature is expected to accept the invocation of principle 167 of the Constitution in the event of such crimes that undermine national interests only by criminalizing and penalizing in the form of discretionary punishments until the enactment of the law by establishing a judicial oversight mechanism.