On Friday, Madam Justice Judianna Barnes Wai-ling jailed Chow for life and adjourned the case of Yim, who was expected to get a one-fourth discount on his jail term for having offered to plead guilty earlier.

Yim’s defence counsel, Christopher Grounds, urged the court to honour the verdicts and borrowed the words of former US president John Adams in his reflection on the Boston massacre trial of 1770.

“As the evidence was,” Grounds said, “the verdict of the jury was exactly right.”

Kwok was reported missing after he joined a night hike on May 27, 2017 to test new equipment with his fellow gamers, including the defendants who were members of a “Midnight Outing Group” on WhatsApp.

His bloodstained body was discovered two days later in a terraced field below a path on Black Hill, with a white gunny sack covering his head and tied around his upper chest. He was certified dead at the scene.

An autopsy conducted found the air-conditioning apprentice had sustained cuts and bruises all over his body, with multiple stab wounds in his neck and a number of impact injuries that fractured his skull.

The cause of death was found to be multiple stab wounds to the neck, and head injury.

Investigators later discovered a pair of broken glasses, an air pistol and a three-foot long metal pipe at the crime scene.

They also identified a number of WhatsApp messages in the months leading up to the hike.

One message from Yim read: “If Benard goes to the checkpoint first, I will probably finish him at the second highest point of Black Hill.”

Then, on the day of the hike: “I take him down with Benard.”

Kwok’s blood was found on a pair of jeans and shoes taken from Chow’s home, and on a rucksack and a pair of boots seized from Yim.

Chow, a Marine Department launch assistant, admitted upon arrest he and Yim had killed Kwok and hid his phone.

Yim also sought to plead guilty to manslaughter, but that was rejected by the prosecution.

Both defendants had denied the killing amounted to murder, with Chow testifying at trial he was acting in self defence after Kwok dashed towards him and attacked him when a discussion over the sale of war-game equipment turned ugly.

Yim, on the other hand, did not testify, but relied on Chow’s testimony to show he was not actively involved in causing Kwok’s death.

His defence counsel, Grounds, highlighted Kwok’s “explosive” character and argued that the messages were not indicative of any plan to harm as phrases like “take him down” were mere war-game jargon, and it would make no sense for the defendants to broadcast such a plan in the WhatsApp group with other members as if they were going to have a “murder party”.

“They talk the talk, but can’t walk the walk,” Grounds said in closing his case on Tuesday. “This is not murder. This is something that went terribly wrong.”

Grounds also reminded the jury the forensic pathologist had been unable to confirm the time of death, so it was unclear whether his client had a duty to stay and check on Kwok to prevent him from bleeding to death.

But prosecutor Martyn Richmond countered that the degree of force Chow applied “simply cannot amount to lawful self defence” and argued there was “a wealth of evidence” from which the jury could infer malice and the intention to kill.

“What happened on the hillside did not happen by accident,” Richmond said. “It was well planned.”

Both defendants had no prior convictions.

Yim was previously charged with a second count of doing an act tending or intended to pervert the course of public justice, to which he pleaded not guilty. The charge was dropped after the judge found there was no case to answer and directed the jury to acquit him.