Peter Gardiner sentenced to life imprisonment for murder of Dillon Willis in Karama in 2021

The youngest of two brothers convicted of murdering a man in a northern suburb of Darwin in 2021 has been sentenced to life imprisonment with a parole period of 20 years.

Peter Gardiner, 23, and Matthew Gardiner, 29, appeared in the Northern Territory Supreme Court on Tuesday after both pleading guilty to the murder of 20-year-old Dillon Willis.

In sentencing Peter Gardiner, the court heard that the two brothers had been drinking in Winnellie on the evening of May 26, 2021, before being driven to Karama armed with what Judge John Burns described in his judgment as an “assortment of knives”.

The court heard that Peter Gardiner approached a group of three people, including the deceased, in the car park of the Karama Shopping Centre.

Mr Willis was then stabbed from behind by Matthew Gardiner with a knife, which Judge Burns described as a series of fatal blows in the “haymaker style”.

Mr Willis then fled, collapsed and lost consciousness.

Judge Burns said it was difficult to determine a motive for the murder.

“The evidence suggests that the deceased was wrongly targeted because he had some problem with a person named Wesley,” he said.

In his verdict, Judge Burns said it was his older brother Matthew who inflicted a series of fatal “haymaker-style” stab wounds on the deceased in the chest.

Although Judge Burns found that Matthew Gardiner caused the fatal injuries, he sentenced the younger brother to life imprisonment for murder. He found that Gardiner had planned the attack with his brother, failed to help the victim and later spoke about it “with an obvious sense of pride.”

During the verdict, family members of Peter Gardiner rose from the courtroom gallery to protest the verdict, verbally abusing his defense attorneys and prosecutors before being removed from the building.

Co-defendant pleads guilty in domestic violence case

In a separate hearing earlier Tuesday, the court heard sentencing motions for Peter Gardiner's brother and co-defendant Matthew Gardiner in connection with the stabbing attack on his former partner Tennaya Stanton-Stevens later that evening.

The court heard that after killing Mr Willis, Matthew Gardiner arrived at Ms Stanton-Stevens' home at around 11.30pm and stabbed the then 25-year-old woman to death during an argument over her recent gambling win.

The court heard that Matthew Gardiner inflicted three large stab wounds, as well as bruising and cuts, on the mother of his two children. She spent five nights in hospital after the attack.

Prosecutor Camille McKay told the court that Matthew Gardiner had been convicted three times of domestic violence against Ms Stanton-Stevens between 2012 and 2019 and was “someone the community needs to be protected from”.

The 29-year-old pleaded guilty to unlawfully causing grievous bodily harm.

He faces a separate, mandatory life sentence for the murder of Mr Willis.

Matthew Gardiner will be sentenced on Friday.