On April 3, 1997, 22-year-old Cho Jung-pil, a student at Hongik University, was killed at a Burger King restaurant in Itaewon, Seoul, South Korea. Cho was stabbed nine times in the neck and chest inside the restaurant's bathroom. Present at the Burger King that night, among a larger group of roughly 20 teenagers, were Edward Lee, a Korean-American, and Arthur Patterson, the son of a US soldier stationed in South Korea. After the rest of the group left, Patterson and Lee encountered Cho in the bathroom, where the stabbing occurred.
The day after the killing, the United States Army Criminal Investigation Division received an anonymous report and arrested Patterson. Lee's father confronted him after seeing his son on television in connection with the case; Lee initially denied involvement but confessed on April 8, 1997, after meeting with a lawyer.
Following what was later described as a botched investigation by South Korean detectives, Lee was convicted of murder while Patterson was convicted only of weapons possession. Lee was subsequently acquitted by the Supreme Court of South Korea due to insufficient evidence. Patterson, who had not been placed under a travel ban, fled to the United States in 1999. Cho's family sued the South Korean government for negligence in allowing Patterson to leave the country, and the Supreme Court ruled in the family's favor.
The case drew renewed public attention in South Korea following the 2009 release of a feature film based on the killing, prompting prosecutors to reopen the investigation and seek Patterson's extradition, indicting him for murder. Patterson was arrested in Los Angeles in October 2011. During the extradition proceedings, a US federal prosecutor overseeing the case stated a belief that Patterson and Lee had acted as accomplices and that evidence pointed to Patterson as the person responsible for the killing. South Korean prosecutors also said they had gathered evidence suggesting Lee had handed Patterson the knife and instructed him to stab Cho. An extradition order was issued by a US District Court in October 2012, though legal challenges delayed Patterson's return.
In September 2015, 18 years after the killing, Patterson was extradited to Seoul to stand trial. He maintained his innocence throughout the proceedings, asserting that Lee was responsible for the killing. In January 2016, Patterson was found guilty of murder and sentenced to 20 years in prison; the presiding judge noted that a life sentence had been considered but was reduced in light of Patterson's age (under 18) at the time of the offense. Patterson appealed, and the sentence was upheld.