The taekwondo master told medical staff that he had been attacked in a supermarket car park, prompting health officials to contact police.
Concerned co-workers of Steven Cho, surprised that the diligent worker they called “the machine” was absent from work, alerted police on Tuesday morning.
Police attended the Watkins Street home the Chos had shared for eight years and found Steven’s body in the entrance.
Police say they found the bodies of Min and the boy in North Parramatta two hours later.
Taekwondo instructor Kwang Kyung Yoo.
They are now working to establish what led to the triple homicide.
“There was no warnings from what we have gathered so far. It was out of the blue. It wasn’t something that was forewarned or planned,” Doherty said.
“We will allege there was murderous intent.”
Yoo remains in Westmead Hospital following surgery.
‘My heart is boiling up again’
Multiple social media profiles operated by Yoo include dozens of videos of children practising and playing at his taekwondo studio, including birthday parties, and of courses he would run at local high schools.
Kwang Kyung Yoo playing soccer with a child in 2022.Credit: Facebook
In one video, Yoo plays soccer with a child in a field under a pink sky as his wife and dog watch on. “Having a precious time with my treasures on the beautiful Sunday afternoon,” he wrote.
But oddities also emerge, including a video in which Yoo has filled out a form requesting to be conferred with the title “Distinguished Senior Professor” from Macquarie University.
“Congratulations Master Lion for your new carrier,” the video is captioned. The university has no record of Yoo.
In the pandemic, Yoo posted photographs of workouts where he flexed his muscles in a dark garage-turned-gym and lamented the lockdown.
“My heart is boiling up again,” he wrote of his lockdown-induced solitude.
“Be strong my students, do not let this madness get you down. We can overcome this madness situation and let’s boiling our passion once more.”
Family and friends of Yoo’s alleged victims are in shock. Steven Cho’s mother was seen at the Watkins Street home inconsolable on Tuesday.
‘He was highly respected’
Colleagues recalled Cho as a man “wrapped up in his work”.
“I have never met a more normal enthusiastic guy in the work environment. He was highly respected in his work at one of the largest construction companies in NSW,” a colleague, who did not wish to be named, told the Herald.
At the time of his death, Cho had worked at Richard Crookes Constructions for nearly two decades and was employed as a senior estimator, the apex of a long career in construction.
The colleague said Cho was referred to among colleagues as “the machine” because he was so good at his job. Such was his reliability that a family friend called police with concerns for his welfare within 16 hours of his death.
Steven Cho’s boss described his “shock and sadness” at the news in an email to staff.
Police are now working with the Australian embassy and its counterparts in South Korea to inform the Cho family.
“It’s a very sad tragedy,” Doherty said.
Police in forensic suits had coated the glass door to the taekwondo studio in fingerprinting dust and evidence stickers by Wednesday morning.
Handprints and smears were visible on the glass, but black plastic sheets kept the scene inside hidden from the public driving by on the way to work.
A blue forensics tent was set up outside the Chos’ Baulkham Hills home.Credit: Rhett Wyman
The Cho’s Baulkham Hills home, inside a sprawling housing complex, was also hidden from view by a blue police forensic tent.
A neighbour, who gave only his first name as Taylor, said he was “shocked” and struggling to form an emotional response to the alleged triple murder.
He was quickly led away by homicide detectives and warned off from speaking to waiting camera crews.