Chilling new details emerge about how a Taekwondo instructor strangled one of his students to death and killed the boy's parents - as his twisted past as a 'status-obsessed, serial liar' comes to light

Daily Mail​

29-05-2025

A taekwondo instructor has admitted to killing his seven-year-old student and the boy's parents as his disturbing history as a status-obsessed serial liar was laid bare in court.
Kyung Kwang Yoo pleaded guilty to three counts of murder at Parramatta Local Court in Sydney 's west on Thursday via video link.
Disturbing court documents have pulled back the curtain on the night Yoo, who was known by his students as 'Master Lion', killed the boy, his mother Min Kyung 'Sue' Cho - 41, and his father Hyun Soo 'Steven' Cho - 39.
On February 19, 2024, the boy arrived at Lion's Taekwondo Martial Arts Academy in North Parramatta at about 4.30pm for his regular Monday night lessons.
He had been a student at the academy for three years and was taking double classes with Yoo to prepare for his upcoming black belt assessment.
Ms Choo was seen arriving the academy about 6.20pm and spoke to Yoo while her son waited in a reception area, the Sydney Morning Herald reported.
CCTV captured the mother following Yoo through a classroom and into a storeroom.
He strangled her to death inside.
When his classes ended at 8pm, Yoo asked the boy to follow him into the same storeroom, where the child was also strangled to death.
Case facts state that after killing her and her son, Yoo took Ms Cho's BMW and drove to her family home in nearby Baulkham Hills.
There he found Mr Cho and repeatedly stabbed him in the head, neck and torso with a knife and a pair of scissors.
Mr Cho attempted to fight off Yoo and inflicted several stab wounds on the taekwondo instructor in self defence.
At about 11pm, Yoo returned to the taekwondo academy to retrieve his phone and Ms Cho's Apple Watch.
He then called his wife and told her he'd been stabbed. The pair decided to meet at a hospital.
While at the hospital, Yoo told police he'd been attacked by three people at a Woolworths car park and had driven his Toyota Camry to the hospital.
No motive for the triple homicide has been confirmed, however a disturbing trend has emerged of Yoo lying about his success, wealth and social status.
One of his lies included being the owner of a BMW.
Weeks before the gruesome murders, Yoo told his wife he would be receiving a BMW from his secondary employer, a local high school.
At about 8pm on the night of the murders, Yoo called his wife to say his BMW had arrived.
Soon after that conversation he drove Ms Cho's BMW to the Cho's family home.
Court documents state Yoo's wife told police he'd driven a friend's BMW that night, which led officers to search the vehicle and discover blood.
Police also found documents for the sale of a multimillion-dollar home in Mosman, papers in the name of 'Professor Kwang Yoo' and a false master's degree from Sydney University.
Detectives claimed Yoo was known to lie to his friends and family about his income, education and family deaths and had an 'obsession' with luxury goods.
His deceptions included telling his family his home had a view of the Sydney Harbour Bridge and he owned a Lamborghini.
Yoo also told his wife and sister he had a PhD and others that he'd competed in the Olympics.
Other associates of Yoo believed both his parents and his wife had died from Covid.
Friends of the Cho family became concerned on the morning of February 20, 2024, and headed to their home.
They called police after spotting an object covered by a blanket.
Officers found Mr Cho's body in the home and headed to Lion's Taekwondo Academy, where blood was found on the building's front step and interior.
The boy's body was found in the storeroom while Ms Cho's body was discovered in an office.
Yoo was arrested at the hospital that evening and has been in custody since.
He will be sentenced in the NSW Supreme Court later this year. The case will next be mentioned on August 1.