Perre faced the South Australian Supreme Court on Friday with Justice Kevin Nicholson confirming his mandatory life sentence for the murder of Detective Geoffrey Bowen and the attempted murder of lawyer Peter Wallis.

With Perre already behind bars for drug offences, Justice Nicholson extended his existing non-parole period by 30 years and seven months.

That means the 65-year-old will be aged over 95 before being able to apply for release.

Justice Nicholson said Perre’s targeted murder of a serving police officer was violent, barbaric and ruthless.

“Your conduct was brutish. That is totally devoid of any human sensibility,” the judge said.

“Your conduct was motivated by matters that do you no credit.

“It was not just premeditated but intricately devised and planned over a lengthy period of time and was executed in cold blood.”

Sgt Bowen died from horrific injuries, including the loss of his left arm, when a parcel bomb built and sent by Perre exploded in his office.

Mr Wallis, who was standing nearby, lost an eye and suffered severe burns in the blast. He died in 2018.

Smoke coming from the Waymouth Street headquarters of the NCA following the bombing in 1994.

Handing down his guilty verdicts in June this year, Justice Nicholson found that Perre had intended to kill Sgt Bowen or anyone else who happened to open the package or be close by when it detonated.

“Mr Perre wanted to kill Mr Bowen but intended the NCA bomb to do its work and kill whomever it did,” the judge said.

Perre was first charged with murder soon after the bombing but the case against him was dropped six months later because of a lack of evidence.

He was arrested again in 2018 after a joint investigation, lasting more than two years, by a number of state and federal authorities including the Australian Criminal Intelligence Commission.

Domenic Perre (left) on the day he was arrested for a second time over the NCA bombing.

In an incredibly detailed and complex case, prosecutors argued the bombing was a personal attack on Sgt Bowen.

They said Perre’s hostility towards him had grown because of their interactions following the seizure of a multi-million dollar cannabis crop in the Northern Territory in August 1993.

Domenic Perre visits Adelaide sites in May as part of the trial which found him guilty of the National Crime Authority bombing. Photo: AAP/Ten News First, Kate Somers

Sgt Bowen’s son Simon, who followed his father’s footsteps into the police force, was just seven at the time of the blast.

“I struggle with the motive and relevance of your actions,” he told Perre in a victim impact statement last month.

“You caused so much irreparable damage and suffering all so you can grow some dope and walk about South Australia like a would-be gangster with your big black glasses.”

Sgt Bowen’s widow Jane Bowen-Sutton said her husband was killed on their ninth wedding anniversary and she had experienced never-ending grief.

“That day I told my seven and five-year-old sons that their much-loved dad had been killed and we would never see him again. I’ve relived that conversation for 28 years,” she said.

Genevieve Wallis, who was eight-years-old when her father was injured, said the attack had left him traumatised, depressed and debilitated.

“The bombing had torn any sense of safety, belonging and privilege of being a child and it sickens me that a blatant disregard for human life can exist within another human,” Ms Wallis said.

Detective Superintendent Des Bray and family members of Geoffrey Bowen and Peter Wallis at a press conference after the Supreme Court in June found Dominic Perre guilty of the 1994 NCA office bombing. He was sentenced on October 7. Photo: Matt Turner / AAP

In defence submissions, Perre’s lawyer Gilbert Aitken told the court that his client sympathised with the families of the victims but maintained his innocence.

He has lodged an appeal against his convictions.

-AAP