A teenager stabbed his former mate in the back and left him to die in a dog park after a fight over a pair of stolen shoes, a court has heard. 

Jarvis Jai Farrier, 21, has pleaded guilty in the Brisbane Supreme Court to the manslaughter of former friend Harrison Geppert at a Gold Coast dog park in September 2019.

The pair’s bitter falling out escalated in the weeks before the attack with social media taunts including images of knives and weapons, prosecutor Mark Green told the court. 

The simmering animosity erupted during a chance encounter on September 4 when the teens crossed paths on their way to buy drugs from the same dealer, he said. 

Farrier was with two others when he bought cannabis at Varsity Lakes.

As he was leaving, he spotted Geppert walking with a friend also on the way to buy drugs from the same dealer.

Farrier called for reinforcements, and the two groups cornered Mr Geppert, blocking both ends of the street.

One of Farrier’s friends accused Mr Geppert of stealing his shoes before the ambush escalated into a physical confrontation between the pair.

Before joining the brawl, Farrier armed himself with a marine-style blade, stabbing Mr Geppert once in his back.

The wound was not deep, penetrating just over 5cm, but enough to puncture Mr Geppert’s left lung before the teen collapsed and died from cardiac arrest.

Farrier and his friends ran from the scene before handing himself to the police later that night.

He told police he believed his former friend was armed with knuckle dusters but never intended to kill the teenager, the younger brother of former Hells Angel bikie Ben Geppert.

He admitted buying the marine knife “in case he needed it” but said the knife “didn’t even go in that far”.

In a victim impact statement read to the court on Monday, Harrison Geppert’s mother Lisa said she could never forgive her son’s killer.

The Geppert family rejected Farrier’s letter of apology and refused to allow him to pay respects at Harrison’s grave.

“Forgiveness, Jarvis, is something you will never get from me. I could never forgive someone who took the life of my child,” Ms Geppert’s statement read.

“I have been living a nightmare I can’t wake up from.

“My 17-year-old son was left in a park alone, to die an excruciating and painful death and you ran. You were a coward.”

Defence barrister David Funch said Farrier was “deeply remorseful” and surrendered to police as soon as he learned of Mr Geppert had died.

“My client didn’t have any intent to cause death or grievous bodily harm,” Mr Funch said.

Justice Elizabeth Wilson described the stabbing as a “deliberate act” before adjourning the sentencing hearing until Tuesday.

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