The crime
On March 29, 2017, an eight-year-old elementary-school student was lured away from a park in Incheon and taken to a nearby residence. The child was killed. The case quickly became one of South Korea's most closely watched criminal prosecutions because of the victim's age, the ages of the defendants and the dispute over how the two defendants had participated.
Contemporary reporting included disturbing details about what happened after the killing. They are not necessary to understand the legal outcome and are not repeated here.
Two defendants, different legal responsibility
The principal defendant, identified in court reporting by the surname Kim, was under 18 when the crime occurred. Prosecutors charged her with kidnapping and murder and sought the maximum custodial sentence available under juvenile law.
A second defendant, surnamed Park, was initially accused of having planned the killing with Kim. At first instance, the court accepted that theory and imposed life imprisonment on Park while sentencing Kim to 20 years.
The appeal changed the case against Park
On April 30, 2018, the Seoul High Court retained Kim's 20-year sentence but rejected the prosecution theory that Park had been proved to be a murder co-conspirator. Instead, the court found Park guilty of aiding the crime and imposed a 13-year prison term.
That distinction is central to this case file. Park is not described here as the person who jointly committed the murder, because the final appellate judgment did not sustain that finding.
Supreme Court ruling
On September 13, 2018, South Korea's Supreme Court rejected the appeals and upheld the appellate judgment. The Court confirmed the 20-year sentence for Kim and the 13-year sentence for Park.
The Supreme Court's own case release states that Kim's kidnapping, killing and disposal-related offenses were upheld, while Park's legal responsibility was upheld as assistance to the killing rather than murder conspiracy. The final judgment therefore resolved both guilt and the different legal roles of the two defendants.
Mental-state arguments
Kim's defense argued that mental-health conditions affected her criminal responsibility. Courts did not accept that argument as a basis for diminished responsibility. This page does not generalize from those claims to autism, dissociative disorders or mental illness more broadly; the issue was specific to the evidence and legal findings in this case.
Timeline
March 29, 2017: an eight-year-old child is kidnapped and killed in Incheon.
September 22, 2017: the district court sentences Kim to 20 years and Park to life imprisonment.
April 30, 2018: the Seoul High Court keeps Kim's 20-year sentence but finds Park guilty of aiding rather than murder conspiracy and imposes 13 years.
September 13, 2018: the Supreme Court upholds the appellate judgment.
Current status
The case is classified as Solved / Adjudicated. The Supreme Court's 2018 ruling made the principal criminal outcomes final: Kim received 20 years for the kidnapping and murder, while Park received 13 years for aiding the crime. The page does not attribute to Park the murder co-conspiracy finding that the appellate court rejected.