NSW taekwondo instructor jailed for life without parole for murder of Cho family over BMW

A taekwondo instructor known by students as 'Master Lion' was sentenced to life in prison without parole in the New South Wales Supreme Court on Tuesday for the murders of Min Kyung Cho, Hyun Soo Cho, and their seven-year-old son, BC, in February 2024. The court said Yoo, 51, killed the family in what Justice Ian Harrison described as a remorseless crime driven by a trivial motive: to obtain the BMW the Cho family owned.

Prosecutors outlined a sequence of planned acts that began inside the Lion's Taekwondo and Martial Arts Academy in North Parramatta, where Yoo operated the studio. After a day of back-to-back taekwondo lessons, Yoo strangled Ms Cho in the storeroom, moved her body to his office, and continued teaching a class while BC waited in the reception area for about 90 minutes. He then returned to the storeroom and killed BC with a pole and a blue ethernet cable. Later that evening, Yoo drove Ms Cho's white BMW X5 to the Baulkham Hills home and fatally stabbed her husband, Hyun Soo Cho.

CCTV and other evidence presented at sentencing showed Yoo had surveilled the Cho residence on five occasions in the weeks leading up to the killings and moved the BMW between locations on the night of the murders. The judge noted that Yoo lied to his wife about a purported job offer and BMW arrangement with a school principal, a deception tied to his mounting financial difficulties. Court records show Yoo was in rent arrears and carried credit-card debt, and he had long known the Cho family through BC, who had studied taekwondo with him and was encouraged to take extra classes to reach his black belt.

In the courtroom, Yoo described the Cho family as a great family to a court-appointed psychiatrist, but his actions told a different story. The day of the murders unfolded in a tightly choreographed sequence. By 6:22 p.m., after the studio had emptied, Yoo lured Ms Cho into the storeroom at 6:23 p.m. and strangled her, then returned to teach before the next class featured a disruption to the ordinary routine. Witnesses heard banging from Yoo’s office about 15 minutes later as he retrieved a baseball bat and a long metal pole, then dragged Ms Cho’s body back into the office and resumed checking on BC, offering him ice blocks to calm him while the boy waited.

At about 7:51 p.m., Yoo called his wife to say that the car had arrived. Minutes later, he took BC into the storeroom and killed him. Over the next 20 minutes, Yoo moved between the storeroom and the office, adjusted the positioning of the bodies, and wore Ms Cho’s Apple Watch on his wrist. When he realized Mr Cho was trying to contact Ms Cho, Yoo closed the studio and drove the BMW to the Baulkham Hills home, where he fatally stabbed Mr Cho in a struggle during which Mr Cho managed to wound Yoo.

Authorities later recovered CCTV footage and other records showing Yoo’s movements and the path of the BMW. In an unusual postscript to the events, Yoo presented himself at Westmead Hospital with injuries and claimed he had been attacked in a supermarket car park the night before, prompting hospital staff to alert authorities. All three bodies were found the following morning, and Yoo was arrested.

A court-appointed psychiatrist described Yoo’s behavior as marked by grandiose fantasies and a pattern of deceit about wealth and status. The report noted that Yoo fabricated meetings with public figures and even claimed Olympic involvement to bolster his image. While the judge found Yoo’s remorse genuine in part—evidenced by a letter addressed to himself in which he expressed sorrow and a desire to turn to God—the psychiatrist’s notes emphasized that the lies and fantasies contributed to an escalating pattern of risk and rationalization for the killings.

Justice Harrison acknowledged Yoo’s early guilty plea but said the crimes were extraordinarily serious and that his risk of reoffending was high. He noted that the killing of BC represented an egregious breach of trust, given that BC was a pupil at Yoo’s martial arts academy and would have looked to him as 'Master Lion.' The judge declined to impose a parole date, effectively ensuring that Yoo will spend life behind bars.

Victim impact statements from Min Cho’s parents described unimaginable grief and the lasting fear their family endured after the deaths. The sentencing marks a somber conclusion to a case that authorities portrayed as a calculated affront to trust and family, carried out in pursuit of a luxury car rather than any legitimate motive. The case stands as a stark reminder of the potential for calculated violence when personal finances, deception and a trusted role intersect in a single, devastating sequence.