Who Bears the Burden of Proof When the Voluntariness of Voluntary Production Is Disputed?

Starting Point of the Case and the Core Legal Question

Supreme Court Judgment 2020Do9431 rendered on March 12, 2024 (Violation of the Act on Special Cases Concerning the Punishment of Sexual Crimes (Taking Photographs, etc. Using Cameras) [a case concerning the admissibility of a mobile phone seized in the form of voluntary production at the time of an arrest in flagrante delicto and of the electronic information stored on it]) squarely addresses the following question: where it is disputed whether a seizure of an article voluntarily produced was a voluntary production under Article 218 of the Criminal Procedure Act, who bears the burden of proving voluntariness?

The Supreme Court's core conclusion may be summarised as follows. Where the voluntariness of voluntary production is disputed, it is not for the defendant to prove grounds for suspicion; rather, the prosecutor must prove matters that dispel doubts as to voluntariness. Because that proof was insufficient, the mobile phone and electronic information in this case must be regarded as illegally obtained evidence and therefore inadmissible. The operative part reads, "The appeal is dismissed.", and the judgment's mode of reasoning is a statement of requirements (following existing precedent).

This analysis follows the structure of the issues, the standards of judgment and the allocation of the burden of proof (to the prosecutor) that appear in the published judgment, and examines why the Supreme Court upheld the conclusion of the court below.

Sources for this section: Supreme Court Judgment 2020Do9431 rendered on March 12, 2024 — official text of the judgment, National Law Information Center

The Structure of the Issues Set by the Holdings and Referenced Provisions

The framework of the holdings as set out in the judgment is as follows: [1] In a seizure of an article voluntarily produced, where it is disputed whether the seized article was actually voluntarily produced under Article 218 of the Criminal Procedure Act, the party bearing the burden of proving its voluntariness (= the prosecutor). [2] In a case concerning the admissibility of a mobile phone seized by the investigative authority in the form of voluntary production at the time it arrested the Defendant in flagrante delicto, in connection with charges of Violation of the Act on Special Cases Concerning the Punishment of Sexual Crimes (Taking Photographs, etc. Using Cameras) alleging that the Defendant, on a total of nine occasions, used the camera of his mobile phone to photograph, against their will, the bodies of four victims in a manner that could arouse sexual desire or shame, the Court held that, in light of all the circumstances, the prosecutor had failed to fully prove matters dispelling doubts as to the voluntariness of the production of the mobile phone, and that the mobile phone and the electronic information stored on it therefore constituted illegally obtained evidence and were inadmissible.

The referenced provisions to be read together in this case are [1] Articles 218 and 308 of the Criminal Procedure Act / [2] Article 14 (1) of the former Act on Special Cases Concerning the Punishment of Sexual Crimes (before being amended by Act No. 15977 on December 18, 2018) and Articles 218, 308, 308-2 and 325 of the Criminal Procedure Act. The first step is to separate, among the constituent elements or the requirements for the arising of a right laid down by the wording of the provisions, how far the domain of statutory interpretation extends and where the domain of case-specific fact-finding begins.

In relation to prior precedent, this judgment sits in the position of following existing precedent. Read alongside the referenced precedents ([1] Supreme Court Judgment 2004Do7900 rendered on November 23, 2006 (Gong2007Sang, 78) and Supreme Court Judgment 2019Do15178 rendered on August 31, 2022), it shows how the Court, while maintaining the outer bounds of the existing legal principle, rearranged the factual elements of the specific case.

Sources for this section: Supreme Court Judgment 2020Do9431 rendered on March 12, 2024 — official text of the judgment, National Law Information Center

Analysis of the Supreme Court's Summary of Judgment and Key Holding Sentences

The core of the summary of judgment set out by the Supreme Court is as follows. [1] In a seizure of an article voluntarily produced, where it is disputed whether the seized article was actually voluntarily produced under Article 218 of the Criminal Procedure Act, it is not for the defendant to prove reasonable and specific facts casting doubt on the voluntariness of the production; rather, the prosecutor must prove matters that dispel doubts as to its voluntariness. [2] In a case concerning the admissibility of a mobile phone seized by the investigative authority in the form of voluntary production at the time it arrested the Defendant in flagrante delicto, in connection with charges of Violation of the Act on Special Cases Concerning the Punishment of Sexual Crimes (Taking Photographs, etc. Using Cameras) alleging that the Defendant, on a total of nine occasions, used the camera of his mobile phone to photograph, against their will, the bodies of four victims in a manner that could arouse sexual desire or shame, the Court upheld as correct the conclusion of the court below, which acquitted the Defendant on the ground that there was no proof of the offence charged, because the prosecutor had failed to fully prove matters dispelling doubts as to the voluntariness of the production of the mobile phone, and the mobile phone and the electronic information stored on it therefore constituted illegally obtained evidence and were inadmissible. The Court so held in light of the following: at the time of the arrest in flagrante delicto, the Defendant was in an intimidated state of mind after his mobile phone had been taken from him by an eyewitness, he even lunged at the eyewitness and police officers to retrieve the phone, and he was being questioned as a suspect after being taken to the police station without the assistance of counsel while denying part of the offences, so whether he voluntarily produced the mobile phone to the investigative authority had to be strictly scrutinised; there was no material establishing that the investigative authority had informed the Defendant, as the person producing the article, of the meaning of and procedure for voluntary production and of the fact that, if he voluntarily produced it, he could not freely obtain the return of the seized item; and it was difficult to conclude that the Defendant was aware that, if he voluntarily produced the mobile phone, he could not get it back even if he later changed his mind, given, among other things, his statement that "a police officer told me, 'the mobile phone can be returned.'"

In particular, the sentence in the judgment that directly supports the conclusion is the following: "It is not for the defendant to prove reasonable and specific facts casting doubt on the voluntariness of the production; rather, the prosecutor must prove matters that dispel doubts as to its voluntariness."

This sentence is not merely an abstract declaration; it serves as the reference point confirming the legal premise on which the judgment of the court below was upheld. From the perspective of the burden of proof, it also specifies the level of objective material that mainly the prosecution must submit.

Sources for this section: Supreme Court Judgment 2020Do9431 rendered on March 12, 2024 — official text of the judgment, National Law Information Center

Key Factors of Judgment Identified in the Judgment and a Record Comparison Table

The table below sets out the factors of judgment to which the Court gave weight in Judgment 2020Do9431 and the role each factor played in the operative part (dismissal).

Sources for this section: Supreme Court Judgment 2020Do9431 rendered on March 12, 2024 — official text of the judgment, National Law Information Center

Competing Readings of the Same Facts

In this case, the court below denied the admissibility of the mobile phone and the electronic information stored on it on grounds including that the voluntariness of the voluntary production of the mobile phone had not been proved, and acquitted the Defendant of the charges at issue. Under the Supreme Court's legal principle, the voluntariness of voluntary production is strictly scrutinised by taking into comprehensive account the defendant's state of mind at the time of the investigation, whether he was informed of the meaning of and procedure for voluntary production and of the fact that he could not freely obtain the return of the seized item, and whether he was aware of these matters.

Accordingly, when analysing similar cases, one should not merely quote the concluding sentence but should test, as a counter-hypothesis, how the conclusion would change if any one of the factors of judgment listed in the table above were absent.

Sources for this section: Supreme Court Judgment 2020Do9431 rendered on March 12, 2024 — official text of the judgment, National Law Information Center

Remaining Questions and Conditions for Revisiting

A follow-up question that remains after reading this judgment is the following: how must the investigative authority explain the meaning of voluntary production and the fact that the item cannot be returned for voluntariness to be recognised?

It is also clear when this analytical framework should be re-examined as further materials or precedents accumulate. This reading should be revisited if Article 218 of the Criminal Procedure Act is amended.

This is a research analysis prepared by comparing the original text and referenced provisions of Supreme Court Judgment 2020Do9431 rendered on March 12, 2024, as published on the National Law Information Center, as of October 15, 2026. It does not substitute for the conduct of litigation by, or legal advice to, any particular party.

Sources for this section: Supreme Court Judgment 2020Do9431 rendered on March 12, 2024 — official text of the judgment, National Law Information Center