Lincoln Ng Jing Kai, 29, was sentenced by the Supreme Court of Western Australia on Nov. 2. He was originally charged with murder but pleaded guilty to manslaughter in August after prosecutors agreed to accept the lesser charge, CNA reported.

His sentence was backdated to May 24, 2024, and he will be eligible for parole after serving three years and nine months.

Justice Terence Palmer said Ng's decision to confront the man and knock him off his e-bike "involved an element of taking the law into your own hands and a degree of vigilantism."

The court heard that Ng was on an eight-day holiday in Perth with his girlfriend and her family, and that he had planned to propose to her.

On May 23, 2024, the man who died, Mark John Burnes, smashed the back window of the group's rental car and took a backpack holding a passport, an iPad, some cash and an AirTag tracker.

That evening, Ng's girlfriend's brother activated the AirTag, saw its location moving and contacted police, who advised him to call back once it had stabilized.

The next day, the AirTag showed up near a construction site. While the group was there looking for it, Burnes rode past on an e-bike carrying what appeared to be the stolen backpack.

The girlfriend's father told Ng to follow Burnes so they would not lose sight of him.

Ng pursued Burnes for about 10 minutes through the streets of the Perth suburb of Carlisle, while the brother stayed on the phone with police.

As Burnes left the road onto a grass verge, someone in the back of the car told Ng to give the bike "a tap," the court heard. Ng hit the e-bike's rear wheel, causing Burnes to fall, then made a U-turn to face him.

Burnes yelled threats at the group. Ng, fearing Burnes might attack and thinking he was coming toward the car, wanted to reverse away. He stepped hard on the accelerator.

The car moved forward and struck Burnes, who went under it. Ng drove off the verge with Burnes trapped under the front driver's-side wheel and continued about 25 meters up the street.

Ng reversed the car, freeing Burnes, and waited by the roadside for police.

Burnes was declared dead in hospital at 2:42 p.m. after sustaining multiple injuries.

An Apple AirTag and the Find My app on an iPhone. Illustration photo by Unsplash/Duc Trinh

Palmer accepted there was a risk Burnes might have been under the car but was not persuaded that the risk was obvious to Ng.

Palmer said Ng should have stopped as soon as he realized the car was moving forward instead of reversing.

In mitigation, the judge considered Ng's guilty plea, lack of criminal history and genuine remorse.

In a victim impact statement included in the sentencing, Burnes' father, Peter Baclay Burnes, said the loss had a huge impact on the entire family, including his son's three children, The Straits Times reported.

Two of the children, one of whom has a disability, have no living parent, he said.