In 2007, the Criminal Procedure Act has been changed into actually new law reflecting the social demands to protect the rights of defendants and suspects in the criminal procedure. The Criminal Procedure Act was revised in 2011, adding the relevance as a requirement of seizure and specifying the range and method of seizure or search on digital evidence. And it supplemented the method of proving the authenticity of digital evidence with some amendments in 2016. It can be said that it has continued to influence the Supreme Court precedent and the precedent also influenced legislation and investigation practice and led to change. This article examines the trends of major cases in the proceedings and evidence law since 2007. The Supreme Court’s cases on investigation procedures and evidence law have consistently emphasized the due process principles of the Constitution and the Criminal Procedure Law, and apply strict standards for existing practices throughout the investigation process including voluntary company, arrest, interrogation, and occasionally have suggested standards and directions of practice from the perspective of judicial control. In particular, in 2007, the Supreme Court ruled that the exclusionary rule of illegally obtained evidence was applied to use of material evidence and the evidence that was illegally collected by the investigating agency in violation of the due process could not be used as evidence of guilt in principle. In the exceptional case that the procedural violation is not equivalent to the violation of the substantive contents of the due process, and the exclusion of the evidence is against the harmonization of the due process and substantive truth in the Constitution and the Criminal Procedure Law, the evidence can be used. Thereafter, the Supreme Court has elaborated the criteria and exceptional jurisprudence on the illegally obtained evidence through various precedents. Since 2007, there have been important precedents related to the seizure of digital evidence, the authenticity and exceptional application of hearsay rule on digital evidence, and specific precedents on the interpretation and standards of exceptional application of hearsay rule of the revised Criminal Procedure Act, which were also the starting point of a new discussion. And this article suggests that, for right judicial justice, the two axes of the due process principle and the request for the discovery of the substantive truth should be mutually realized in harmony rather than abandoning any one.

After 2000, the Supreme Court of Korea did not follow just its former rulings in some criminal procedure cases. Rather the Court has chosen to underscore due process in the Korean Constitution and the Criminal Procedure Act and proceed to present more strict standards on usual practices. And in the first decade of the 21st century, the National Assembly, the Court, the Prosecutors' Office, and the academic circles have continually exerted influence over one another. As a result, the Criminal Procedure Act was revised in 2007 and took effect on and after Jan. 1, 2008. In this article, some supreme court cases in the criminal procedure are reviewed. These cases involve the exclusionary rule, the right to counsel, the admissibility of statements, and digital evidence, which are related to the revise of the Act or the change of practical routines. The revised Act introduced the exclusionary rule to the criminal justice system. The Court refused to apply the rule to the illegally obtained physical evidence. But it changed the former rulings in Supreme Court 2007. 11. 15. 2007do3061 and held that, in principle, the exclusionary rule and the fruit of Poisonous Tree doctrine should be applied to physical evidence if the evidence was obtained by the search or seizure which violated the process of the Constitution and Criminal Procedure Act. In Supreme Court 2011. 5. 26. 2009mo1190, the Court affirmed the courts' practice which made a limitation on the executive way of search and seizure warrant by the additional notes. And that ruling led the newly establishment of the article 106 ③ of the revised Act. In November 2003, the Supreme Court of Korea held that a suspect in custody had the right to counsel during interrogation. And in September 2004, the Constitutional Court of Korea determined to confer the right to counsel on a suspect without custody. After these decisions, the Criminal Procedure Act had an explicit provision for the right in 2007. On the other hand, the Court had maintained its rulings that if the formal authenticity of the statements by a suspect in the protocol of prosecutor is affirmed, the substantial authenticity of the statements was presumed and might be admissible. But the Court changed its former rulings in Supreme Court en banc 2004. 12. 16. 2002do537 and held that the substantial authenticity may also be affirmed only by an admission of the author. And in case of digital evidence, the Court has told that digital evidence may be admissible only if it falls under the hearsay exceptions where it is testimonial.