Murderer sentenced after father stabbed

All Benjamin Suttie did was say hello.

Yet moments later the friendly 37-year-old was fatally stabbed in front of his son by Harley David Wegener.

"Ben Suttie's only mistake that night was to show a degree of community spirit with good-natured chit chat," crown prosecutor Greg Cummings said.

Wegener responded aggressively to Mr Suttie's greeting as their respective groups passed in a park south of Brisbane in August 2018.

The chance, late night encounter at Woodridge quickly escalated.

After a scuffle, Wegener produced a knife with "scalpel-like" sharpness, slashing at Mr Suttie's face and then throat.

His carotid artery was sliced in half.

His son Zac Elder - then aged 19 - took his shirt off to try and stop the blood spurting out of his father's neck.

But Mr Suttie was already "doomed".

"The final moments of Mr Suttie's consciousness must have been terrifying for him," Justice Melanie Hindman said.

"The bloody, horrific scene that confronted Mr Suttie's group including his own son I am sure will endure in their memories."

Mr Suttie would have required surgery within minutes to survive, Wegener's recent two-week murder trial heard.

His life support was turned off days later after multiple organ failure caused by severe blood loss.

Mr Elder was among Mr Suttie's family and friends at Wegener's Brisbane Supreme Court sentencing for murder on Thursday.

"Harley you are not tough. You are the weak man here," Mr Elder said in his victim impact statement.

"I honestly feel Harley Wegener doesn't deserve to breath the same air ... this man disgusts me."

Mr Suttie's sister, Jody Proctor, said her family felt like lost souls, but had tried to rally around another of his siblings while she battled cancer.

"He (Mr Suttie) would have been her biggest supporter," she said before breaking down while reading her statement.

Wegener had claimed at his trial that Mr Suttie started a fight and he had merely pushed at the Queensland dad while holding a knife.

Wegener's defence barrister had also told the jury that it may have been an "error of judgment" by Mr Suttie that led to the fatal encounter.

"Our son was made out to be the devil when in reality Ben didn't have a bad bone in his body," Mr Suttie's mother, Lesley Proctor, said in a heartbreaking victim impact statement.

Wegener, 34, told the jury he carried around a 30cm knife to feel safe in the "pretty rough" Woodridge neighbourhood, but did not intend to hurt anyone.

However, the court heard Wegener had a long criminal history since he was 17, including knife offences.

He had avoided a significant jail term despite being found guilty of knife violence, threats and possession.

On one occasion he was arrested with "six knives clearly visible".

Wegener also took part in a prison riot that caused $70,000 worth of damage while on remand for the murder charge.

"You have been given so many opportunities to change your behaviour and did not take advantage," Justice Hindman told Wegener.

The Crown asked Justice Hindman to exercise discretion and extend Wegener's sentence to 21 years.

However, Wegener received life with a non-parole period of 20 years.

"I hope you rot in hell," Mr Suttie's mother told Wegener.