This study analyzes criminal liability for the illegal possession and control of firearms by civilians under Emergency Law Number 12 of 1951. It employs a normative juridical approach through the examination of legislation, legal literature, and Decision Number 370/Pid.Sus/2016/PN-Mdn. The analysis focuses on three aspects: law enforcement, the imposition of criminal sanctions, and supervision by the Indonesian National Police. The findings show that unauthorized firearm possession constitutes a serious criminal offense punishable by death, life imprisonment, or imprisonment for up to twenty years. Nevertheless, enforcement remains constrained by weak institutional structures, inconsistent sentencing, limited supervision, and low public legal awareness. The imposition of a relatively lenient sentence in an illegal firearm possession case also reveals a gap between the severity of the statutory penalty and judicial practice. Therefore, regulatory strengthening, consistent sentencing, improved administrative and operational supervision by the National Police, and broader public legal education are required. These measures are essential to establish a more effective, proportionate, and public-safety-oriented firearm control system.