Graphic Details Revealed In Family's Triple Murder by Son's Taekwondo Instructor

Kyung Kwang Yoo -- owner of Lion's Taekwondo and Martial Arts Academy in Sydney -- pleaded guilty to three counts of murder on Thursday via video link, in the deaths of Min Kyung Cho, 41, her husband Hyun Soo "Steven" Cho, 39, and the couple's 7-year-old son, Benjamin.

Along with his plea came the agreed facts of the crime, detailing how Yoo killed all three victims, as well as his claims he himself was attacked after showing up to the hospital with stab wounds after murdering Steven.

The murders went down on February 19, 2024, after Benjamin and his mother showed up to the academy for classes; the boy was training for his black belt at the time.

Per the docs, via the Sydney Morning Herald, the child arrived for his first class at 4:30 pm, before his mother entered the studio at 6:20 and was seen speaking with Yoo. She then followed the instructor into a storage room, where she was strangled.

Yoo then finished the class, called his wife to say he had been given a new BMW from his second job and then brought the boy into the same storage room and strangled him to death.

The BMW he told his wife about, it seems, was actually Min's -- and something he told his wife he would be receiving weeks before the murder.

After killing the first two victims, Yoo then took Min's vehicle to the couple's home and confronted her husband. Per the statement of facts, Yoo stabbed the man with both a knife and scissors in the head, neck and torso.

Steven, however, fought back -- and Yoo was left with several stab wounds of his own. He returned to his studio and called his wife, saying he had been stabbed and needed to go to the hospital.

At the hospital, he told authorities he had been attacked by three people in a parking lot. His wife then told police he had been driving a BMW that evening, prompting a search of that vehicle; inside, they found blood, as well as a falsified master's degree in Yoo's name, among other documents.

Steven's body was discovered by concerned friends the next day, before police found his wife and son inside Lion's Taekwondo Academy, where they had been left by their killer. Yoo was then arrested at the hospital that night.

No real motive has been revealed for the brutal crimes, though the docs state Yoo was a compulsive liar who was known to make up stories about his income, education and possessions; he also allegedly has an "obsession" with luxury items.

He'll be sentenced later this year.

Per NBC News, the maximum sentence for someone convicted of murder is life imprisonment, a standard non-parole period of 20 years for the murder of an adult and 25 years for the murder of a child.