Taekwondo instructor Kwang Kyung Yoo’s phone call to wife after murdering student’s mother

A taekwondo instructor who slaughtered an entire family and stole one of their cars rang his wife amid the killings to tell her he had obtained a BMW, court documents reveal.

Kwang Kyung Yoo, 50, on Thursday pleaded guilty to the February 2024 murders of his seven-year-old student and the boy’s parents, Min Cho, 41, and Steven Cho, 39.

Yoo strangled the mother and son at his North Parramatta taekwondo studio before driving her BMW to the family’s Baulkham Hills home, where he assaulted and stabbed her husband.

Now, new revelations about the horrific slayings have been laid bare as a statement of agreed facts was tendered in Parramatta Local Court last week.

While a clear motive for the killings wasn’t outlined, the documents reveal Yoo was a serial liar who was obsessed with luxury items, wealth, and social status.

According to the documents, the martial arts instructor — who was known as “Master Lion” to his students – consistently told grandiose mistruths to friends, family, and students about his success, wealth, and academic and sporting credentials.

In January 2024, just weeks before the murders, Yoo lied to his wife that he was being given a BMW — the same make as the Cho’s car — as a work car from his secondary employer, a local school.

He was also captured on CCTV driving into the housing complex where the family lived on five separate occasions in the 11 days leading up to the murders.

According to the court documents, the tragic turn of events began when the seven-year-old boy arrived at Lion’s Taekwondo and Martial Arts Academy about 4.30pm on February 19 last year ahead of his regular Monday night classes.

The boy, who had been attending the school for three years, was taking double classes with Yoo in preparation for his black belt.

CCTV footage shows Min arriving at the studio about 6.22pm, after the other parents and students had left.

While the boy waited in reception, Min followed Yoo through the classroom to the storeroom, where he strangled her, before dragging her body into the office.

After the class with the boy finished just before 8pm, Yoo called his wife to tell her “the car has arrived”.

He then lured the seven-year-old boy into the storeroom and strangled him, according to the facts.

At 8.48pm, Yoo drove Min’s BMW x5 to the family’s Baulkham Hills townhouse, where he broke in and waited for half an hour for Steven to arrive home, before stabbing him repeatedly in the head, neck, and torso with a knife and pair of scissors.

The facts state Yoo suffered several stab wounds as Steven fought for his life.

Yoo drove back to the studio and collected his phone and Min’s apple watch about 11pm, according to the documents.

He then called his wife and told her he had been stabbed and agreed to meet her at Westmead Hospital.

At the hospital, Yoo was treated for a collapsed lung and told police he had been attacked by three people in North Parramatta Woolworths car park and he had driven himself there in his Toyota Camry.

According to the facts, police spoke to Yoo’s wife and learned he had told her he had been driving a friend’s BMW, which led police to search that vehicle.

The facts state police discovered blood inside the BMW, as well as documents for the sale of a multi-million dollar home in Mosman, a false master’s degree from Sydney University in his name, and papers in the name of “Professor Kwang Yoo”.

Steven’s body was discovered the next day when concerned friends went to the couple’s home. They saw an object covered by a blanket and called police.

Police then went to the martial arts studio, where they noticed blood on the front steps before finding the bodies of Min and her son inside.

The documents reveal Yoo was a prolific liar, who told people that he had competed in the Olympics, that both his parents and wife had died from COVID-19, and that he owned a Lamborghini and a home with views of the Harbour Bridge.

He also inspected properties and falsely told agents he was acting on behalf of his wealthy employer or his parents who had a budget of up to $50 million and also attended a car dealership to discuss purchasing a Lamborghini.

He also told others, including his wife and sister, that he had achieved a PhD from Macquarie University and Sydney University, however, both institutions had no record of him.

Yoo will be sentenced in the NSW Supreme Court later this year.