A 24-year-old South Korean man assaulted his girlfriend 514 times over three hours and 20 minutes, causing her death. The case aired on SBS's Unanswered Questions.

A man beat his girlfriend 514 times over the course of three hours and 20 minutes, resulting in her death. The case, known as the Gangseo torture murder, was covered by SBS's investigation show "Unanswered Questions" on October 24.

On June 20, at about 2:20 PM, 24-year-old Jeon reported that his 28-year-old girlfriend had lost consciousness. When paramedics arrived at their below-ground apartment, the victim, known by the pseudonym Im Jan Di, was already in cardiac arrest.

Police were present at the scene, and Jeon admitted to them that he had assaulted her. He claimed he had struck her several times using a rubber mallet, said he had no intention of killing her, and stated he had been triggered by her "lies."

An autopsy found that Im had 21 broken ribs and multiple ruptured internal organs. A home security camera captured the incident, which forensic experts described as "torture."

The production team also analysed Im's phone and found a bizarre project the couple was working on. They found the term "gukpeu" used often between the two, short for "gukga peurojekteu" or national project. Jeon told the team it referred to a fictional country the couple had created, called "Dduri Kingdom."

For this country, they had set up rules the couple agreed on to help them fight less. These included "the moment you choose to lie, you are no longer entitled to any humane treatment" and "once punishment begins, no plea or explanation is possible." It also stated that "punishment will exceed whatever you can imagine." Only Jeon was permitted to carry out punishments.

Im's phone also contained records that she had used AI multiple times to formulate responses to Jeon's riddle-like questions.

Im's coworkers remembered her as someone kind and diligent, although her behaviour had noticeably changed a year earlier. She reportedly stepped away to take phone calls in emergency stairwells and came to work with bruises on her face or with a limp. She had never asked anyone for help.

Jeon's peers described him as stubborn and single-minded, unable to control his emotions. It was noted that being around him was uncomfortable, as conflicts would arise over trivial matters. Jeon's parents, however, claimed that Im was the one who "gaslighted" him.

He has expressed his intention to support Im's family for the rest of his life and to seek their forgiveness.