The Korean Constitution and the Korean Criminal Procedure Code provide the emergency arrest exception for the warrant requirements. The investigative authorities can arrest suspects without an arrest warrant issued by a judge if there is "probable cause" to believe that a suspect has committed a felony and if there is concern to believe that the suspect may destroy evidence or attempt to escape. In the case of an emergency arrest, the Criminal Procedure Code does not require that an arrest warrant be filed within 48 hours but it only requires that a detention be filed, therefore, the warrantless arrest without any judicial control is legitimatized for at least 48 hours. As a result, the investigative authorities tend not to pursue the arrest on the warrant, but depend on the emergency arrest because it is free of any warrant requirement and gives them much time to interrogate the suspect without any judicial control. In addition, the investigative authorities have developed two kinds of convenient systems to avoid the warrant requirement. The first is "voluntary accompaniment," which is the Korean version of the U.S. Terry stop system. The second is "investigation of relevant persons" who voluntarily appear before the authorities following the authorities' request to come to the police station although they are not a suspect. Since these two systems are not officially a compulsory measure, the constitutional restrictions for an arrest warrant do not attach. In particular, the authorities often proceed these two systems first, try to acquire informations from citizens, then arrest citizens if they are not cooperative. This Article is to review two Korean Supreme Court decisions to deter these two investigative authorities' tactics. The Decisions of July, 6, 2006 provides strict requirements of permissible "emergency arrest" of the "relevant persons" who voluntarily appear before the authorities. The Decisions of September, 8, 2006 stablished that if the individuals who are asked to voluntarily accompany the officer to the police station are not given the "freedom to leave" at any time, as a practical matter, the "voluntary accompaniment" is an illegal arrest.