"Need for Sophisticated Legal Framework on the Scope of Seized Evidence in the AI Era"...Attorney Kijung Sung

Published 24 Jul.2025 07:05(KST)

Kijung Sung of Bae, Kim & Lee LLC Publishes "The Legal Principles of Search and Seizure"
Key Issues: Relevance, Right to Participate, and Disposal of Irrelevant Information

Search and seizure is one of the most powerful and controversial forms of compulsory measures in criminal proceedings. Especially in the IT era, disputes over the legality and admissibility of evidence have been unceasing. As digital devices, including mobile phones, now contain nearly all information about daily life, how investigative authorities seize and utilize these devices continues to be a key issue that can determine the outcome of trials.

Kijung Sung, Attorney at Law, Bae, Kim & Lee LLC. Legal Times.

Kijung Sung, attorney at law at Bae, Kim & Lee LLC, who has acutely experienced these changes in practice, recently diagnosed that "relevance," "right to participate," and "disposal of irrelevant information" have become the core issues in the field of search and seizure. Having participated in more than 3,000 hours of search and seizure operations over the past decade, he has recently published "The Legal Principles of Search and Seizure" (published by Pakyoungsa), a book that compiles major precedents and legal theories applicable to the field, based on his practical experience.

When met at the Bae, Kim & Lee LLC headquarters in Sogong-dong, Jung-gu, Seoul on July 17, Sung commented on the case of Samsung Electronics Chairman Lee Jae-yong, whose acquittal was confirmed on the same day, saying, "Most of the key issues discussed in the field of search and seizure were contested in this representative case," and explained, "Both the first-instance and appellate court rulings contain detailed judgments on the major issues."

At the time, the appellate court ruled that the servers of Samsung Bioepis and Samsung Biologics, submitted by the prosecution, were illegally collected evidence and therefore inadmissible. The court found that it was difficult to recognize the existence of a search and selection procedure or substantial guarantee of the right to participate during the search and seizure process. On July 17, the Supreme Court upheld the original acquittal as it was.

The Digital Investigation Era: Recent Trends and Legal Challenges in Search and Seizure

Sung cited Supreme Court Decision 2020Do3050 as a particularly notable recent case. In this case, investigative authorities stored information unrelated to the warrant's charges on the Supreme Prosecutors' Office server during the search and seizure of a mobile phone and later used it for a separate investigation. The court found this to be illegally collected evidence. The Supreme Court held that "even after selectively seizing relevant information, retaining irrelevant information is illegal, and the illegality is not cured even if a warrant is later obtained for the irrelevant information," thereby denying the admissibility of both the information and any derivative evidence.

Sung also explained that the right to participate is another practically significant issue. "From the perspective of investigative authorities, the right to participate may not seem important, but courts are increasingly taking a stricter view regarding the guarantee of participation rights," he said.

Based on these points, he emphasized the need for further development of legal principles regarding the "use of lawfully seized evidence for separate cases." Sung stated, "Current case law generally holds that 'there are no restrictions on the use of lawfully seized materials,'" adding, "In an era where artificial intelligence technology is being introduced into the work of investigative authorities and courts, a more sophisticated legal framework must be established for the scope of use of seized materials."

Hoping the Book Serves as a Reference for Search and Seizure

Sung explained that the motivation for writing the book was to "help junior attorneys reduce the burden of research by organizing the materials."

The book organizes statutes, administrative rules, and Supreme Court and lower court precedents regarding the legality of search and seizure and the admissibility of seized evidence, by procedure and by issue. In particular, he focused on minimizing subjective interpretation and faithfully reflecting the legal principles set forth in court decisions.

Sung stated, "Not only attorneys, but also judges, prosecutors, and investigators can use this book as a reference," adding, "It contains a wealth of both positive and negative examples of arguments that can be made in disputes over the admissibility of evidence related to search procedures, so it should be very helpful in practice." He concluded, "Since case law related to electronic information search and seizure is rapidly accumulating every year, I am considering revising the book annually."