Open Decision Ledger · Capital markets & finance
Requirements for Establishing Joint Principal Offender Liability and the Degree of Proof Required for Joint Intent in a KOSPI 200 Index Market Manipulation Case
Translated from the Korean original. Read the Korean
Supreme Court, Dec. 21, 2023, 2018Do20415 (judgment)
No holding summary · checked against points at issue. The official text publishes no summary of the holding for this decision. The quotation and factors in this record are copied verbatim from the points at issue; the evidence for each axis is taken from the points at issue, the order and the reasons.
Case name: 자본시장과금융투자업에관한법률위반
Official text on the National Law Information Center
Question
In a case involving a violation of the Financial Investment Services and Capital Markets Act on the ground of manipulation of the KOSPI 200 index, to what extent must joint intent and functional control over the conduct be proven in order to recognize a defendant as a joint principal offender?
Holding
A joint principal offender requires joint intent and the commission of the crime through functional control over the conduct exercised pursuant to that joint intent. Joint intent is not established merely by recognizing and condoning another's offense; a relationship of mutual utilization, in which the parties make use of each other's conduct, must be proven beyond a reasonable doubt. The Supreme Court found that no such proof existed and upheld the court below's judgment declaring a not guilty verdict.
Points at issue, verbatim
형법 제30조의 공동정범이 성립하기 위한 요건
Unofficial English translation
Requirements for establishing joint principal offender under Article 30 of the Criminal Act
Disposition
Dismissed Stated in the decision
상고를 모두 기각한다.
Unofficial English translation
All appeals are dismissed.
Form of the test
Elements stated Stated in the decision
공동정범이 성립하기 위해서는 주관적 요건인 공동가공의 의사와 객관적 요건인 공동의사에 의한 기능적 행위 지배를 통한 범죄의 실행사실이 필요하다
Unofficial English translation
In order for a joint principal offender to be established, there must be a joint intent to commit a crime, which is the subjective requirement, and the fact of commission of the crime through functional control of the act by a joint decision, which is the objective requirement
Factors
- 형법 제30조의 공동정범이 성립하기 위한 요건
- 주관적 요건으로서 공동가공 의사의 내용
- 공동정범으로 인정하기 위한 증명의 정도
Unofficial English translation
• Requirements for establishing joint principal offender under Article 30 of the Criminal Act
• Content of the joint intent to commit a crime as a subjective requirement
• Degree of proof required to recognize a joint principal offender
Relation to precedent
Follows earlier decisions Stated in the decision
대법원 2005. 3. 11. 선고 2002도5112 판결
Unofficial English translation
Supreme Court Decision 2002Do5112 decided March 11, 2005
Decisions referred to
대법원 2005. 3. 11. 선고 2002도5112 판결(공2005상, 618), 대법원 2018. 5. 11. 선고 2017도21033 판결
Burden of proof
The prosecution Read from the decision
그와 같은 증명이 없다면 설령 피고인에게 유죄의 의심이 간다 하더라도 피고인의 이익으로 판단할 수밖에 없다
Unofficial English translation
If there is no such proof, then even if the defendant is suspected of being guilty, the matter cannot but be determined in favor of the defendant
Open question and revisit condition
In market manipulation offenses, to what extent must the provision of ideas or involvement in the establishment of speculative positions reach before it is evaluated as functional control over the conduct, as an essential contribution to the offense?
This reading will be reviewed again if Supreme Court precedent on the joint intent or functional control over the conduct of a joint principal offender changes, or if the provisions of the Financial Investment Services and Capital Markets Act punishing market manipulation are amended.
Cross-family AI independent reading & axis check
7 of 8 axes matched GPT-6 Astra (OpenAI, codex CLI) · 2026-10-16
In a comparison with an independent reading by another AI (GPT-6 Astra), which read only the original text without seeing the first reading, 7 of the 8 axes matched, and the readings diverged on the seventh axis (Burden of proof).
Axis 7 (Burden of proof): Primary “The prosecution” vs Independent “Not addressed”
Because the original text specifies only the degree of proof required for recognizing a joint principal offender, the first reading may connect this to the prosecution's burden of proof, while the independent reading may place weight on the absence of any express identification of the party bearing that burden.
그와 같은 증명이 없다면 설령 피고인에게 유죄의 의심이 간다 하더라도 피고인의 이익으로 판단할 수밖에 없다Raw responses and comparison record: Protocol · Blind readings (JSONL) · Axis comparison (JSONL) · SHA-256 (JSON)
Lower-court contrast & scope of application
Lower-court reading vs. Supreme Court holding
Lower-court context: The court below (Seoul High Court Decision 2016No603) held that, on the evidence submitted by the prosecution alone, it is difficult to find it proven beyond a reasonable doubt that Defendant 1 recognized and condoned the fact that the co-defendants at first instance were establishing speculative positions profiting from a decline in the KOSPI 200 index and manipulating the index, or that Defendant 1 made an essential contribution to the offense under a common intent and thereby exercised functional control over the conduct; it therefore reversed the first instance judgment, which had found the defendants guilty, and entered a not guilty judgment.
Supreme Court standard: After confirming the existing legal principles on the requirements for establishing joint principal offender liability and the content of joint intent and the degree of proof, the Supreme Court found no error in the court below's holding, whether by exceeding the limits of the principle of free evaluation of evidence or by misunderstanding the legal principles concerning conspiracy and functional control over the conduct, and dismissed all final appeals.
Distinguishing conditions
- Where it is concretely proven on the Records that the defendant made an essential contribution to the offense, such as by establishing speculative positions or devising the method of market manipulation
- Where explicit communication of intent and a division of roles for the offense among the accomplices are revealed and a relationship of mutual utilization is confirmed
- Where the defendant is prosecuted not as a joint principal offender but as an abettor or a sole principal offender, so that joint intent is not at issue
Record verification notes
Before asserting the same not guilty conclusion, one must check whether the Records contain evidence showing that the defendant's status and role throughout the entire process of the commission of the crime, the contents of any encouragement directed at the accomplices, and the like go beyond mere recognition and condonation to demonstrate a relationship of mutual utilization.
From the official text
Points at issue
형법 제30조의 공동정범이 성립하기 위한 요건 / 주관적 요건으로서 공동가공 의사의 내용 / 공동정범으로 인정하기 위한 증명의 정도
Unofficial English translation
Requirements for establishing joint principal offender under Article 30 of the Criminal Act / Content of the joint intent to commit a crime as a subjective requirement / Degree of proof required to recognize a joint principal offender
Summary of the holding
The official text publishes no summary of the holding for this decision. The quotation and factors in this record are copied verbatim from the points at issue; the evidence for each axis is taken from the points at issue, the order and the reasons.
Order
상고를 모두 기각한다.
Unofficial English translation
All appeals are dismissed.
Provisions referred to
형법 제30조, 형사소송법 제308조
Read 2026-10-16 · Cross-read 2026-10-16. All quotes matched against the official text. The Chinese-character placeholders the court used for anonymised parties are given in their Korean readings, and parenthetical Chinese-character glosses are omitted.
Every entry is published only after all quotes have been matched character by character against the official text, and audited by an independent second reading from a different model family across all eight axes. Both agreed axes and text-grounded interpretive divergences are recorded openly. The ledger is a research record, not an assessment of the court or advice on any matter.
Back to the ledger