다수 과실행위의 경합과 형사책임의 판단 - 가해자 불명의 공동불법행위와 관련하여 -

This article examines the Supreme Court of Korea’s Judgment of March 9, 2023 (2022Do16120) - the so-called “cigarette-butt fire” case - through the lenses of the act/omission distinction, the doctrine of simultaneous offenders (Korean Penal Code art. 19), and the foundations of commission by omission and duties to act. Drawing on the civil-law doctrine of joint torts involving unidentified tortfeasors and comparative references including Summers v. Tice (U.S.), it explores principled solutions to “Joint tort with unidentified tortfeasor” scenarios within criminal law. The case concerned two workers who, amid strong winds near a recycling storage site, each discarded a cigarette butt shortly before a fire broke out. The direct causative act could not be pinned on either individual. The appellate court and the Supreme Court rejected ‘co-principal liability in criminal negligence’, yet imposed liability for negligent arson as an omission offence, recognizing in each defendant a duty to remove the other’s smoldering butt. From the perspective of simultaneous offenders (art. 19), however, where the causative act remains unidentified, liability for negligent arson by act can at most amount to a non-punishable attempt; pivoting to omission to circumvent this evidentiary gap is unwarranted. In effect, the Supreme Court’s approach approximates the outcome of ‘co-principal in criminal negligence’, risks distorting the rationale of the simultaneous-offenders doctrine, and tilts the burden of proof away from the prosecution toward the defendants. The article further argues that the act/omission line should be drawn by normative evaluation - the “Schwerpunkt der Vorwerfbarkeit” (center of blame) - rather than external form. In this case, the center of blame lies in the act of discarding the cigarette, not in the subsequent failure to remove it; criminalization based solely on the latter warrants caution. It also questions deriving a guarantor status broadly from contractual good faith in the workplace, which risks over-expansion of criminal liability. In criminal adjudication, the presumption of innocence and a stringent burden of proof must be preserved, while victim compensation can be addressed through the civil-law doctrine of joint torts with unidentified tortfeasors. In conclusion, where multiple negligent acts concur and the causative act cannot be pinpointed, a sound approach is: (1) draw the act/omission line by normative evaluation(Schwerpunkt der Vorwerfbarkeit), (2) apply the simultaneous-offenders doctrine faithfully to maintain clear limits on criminal liability, and (3) utilize civil-law mechanisms for victim redress. This two-track solution prevents overreach of penal power while strengthening both the substantive and procedural legitimacy of criminal responsibility.