6 Australian murderers whose crimes were so horrific they'll never be released from jail.

Warning: This post contains mentions of domestic violence, and graphic descriptions of violence and murder, and may be triggering for some readers.

On September 3, 2018, 25-year-old Robert Harvey committed five counts of murder in his Bedford, Perth home.

In his wake were the bodies of his three-year-old daughter Charlotte, two-year-old twins Alice and Beatrix, their mother, Mara Lee Harvey, 41, and grandmother, Beverley Ann Quinn, 73, all of whom were stabbed multiple times.

According to the details from his trial, Harvey planned the attacks for days, with the ABC reporting that the business owner stayed with the bodies for five days, which he “photographed after covering them with blankets and bunches of flowers”.

WA Police Commissioner, Chris Dawson on the string of domestic-family related deaths which occurred in Western Australia in 2018.

Handing down Harvey’s sentence during his trial on July 19, Justice Stephen Hall said there was “no other case that is truly comparable,” delivering a ‘never to be released’ order. This means Harvey will be imprisoned for life, without a chance of parole.

“Your actions are so far beyond the bounds of acceptable human conduct that they instil horror and revulsion into even the most hardened of people,” he said.

“It is necessary to make an order that you never be released in order to meet the community’s interest in punishment and deterrence.”

This also makes Harvey the first person in Western Australia to receive a 'never to be released' order, which was introduced under state homicide laws in 2008. Unlike standard 'life imprisonment sentences,' which carry a non-parole period determined at sentencing, he will be eligible for parole during the entirety of his sentence.

According to a News.com.au article from 2016, there are less than 15 out of 1019 prisoners with life sentences who have been refused non-parole periods. The punishment is given to criminals who've committed grievous crimes, do not show remorse for their actions, and are at risk of re-offending or endangering their community.

These are some of Australia's other notorious criminals who've been given that punishment.

Peter Dupas

Victorian serial killer, Peter Dupas, was convicted of three brutal murders, and has been serving three life sentences for murder without parole since August 22, 2000.

His first victim, Nicole Patterson, a 28-year-old psychotherapist, was found with 27 stab wounds to her chest and back. Her breasts had also been removed from her body, and have never been recovered.

For this crime, Judge Frank Vincent sentenced Dupas to life imprisonment without the opportunity for parole, stating that his rehabilitation was "so close to hopeless".

"There is no indication whatsoever that you have experienced any sense of remorse for what you have done, and I doubt that you are capable of any such human response," he said.

In 2010, Dupas was found guilty of the murder of Mersina Halvagis, who he killed while she was visiting her grandmother's grave. Four years later, he was also sentenced for the 1997 murder of sex worker Margaret Maher.

Michael Cardamone

In 2017, Victorian man Michael Cardamone became the first person in the state to receive a life sentence without parole, without having any prior murder convictions.

After being released on parole for the rape of a 15-year-old girl, he murdered his neighbour, mother-of-two Karen Chetcuti, in January, 2016. Cardamone bound, gagged and sedated the 49-year-old woman with animal tranquilliser, injected her with methamphetamine and battery acid, and burnt her alive. He also repeatedly drove over her body with his car.

While sentencing Cardamone to life without parole, Justice Lex Lasry called the crime "horrifying, depraved and disgusting".

"Ms Chetcuti must have gone through an extended period of suffering before her death and in all likelihood spent the hours she was conscious expecting to be murdered," he said.

"To refuse to fix a minimum term is an exceptional step and is a dreadful punishment, but this was a dreadful crime."

Katherine Knight

Dubbed Australia's Hannibal Lecter, Katherine Knight's 2000 murder of her partner, John Price, made her the first woman in Australia to be sentenced to life imprisonment without parole.

An abattoir worker from NSW's Hunter Valley, the mum-of-four stabbed Price 37 times, before skinning him and hanging his skin on a meat hook in her living room. She then proceeded to cook his head and parts of his buttocks with the intention of feeding it to his children.

Writing about the crime in the book, Fatal Females, The Black Knight, author Libby-Jane Charleston describes the carnage that came after Knight's murder:

Once she’d removed the skin, Knight continued to degrade the body by chopping off Price’s head and cooking it in a large pot on the stove with some vegetables, like a sickening stew. Parts of his buttocks were also sliced off and baked in the oven, together with a selection of peeled vegetables. The gruesome steaks were then arranged on plates with the vegetables and left as meals for his children.

Another piece of his buttock was thrown into the backyard, perhaps for the dogs.

Bizarrely, this stomach-churning cook-up was all happening in the early morning, way before dinner time, and Knight was getting so well prepared she even made some gravy to serve with the meal, in addition to writing vindictive handwritten notes to Price’s children.

Administering her sentence, Justice Barry O'Keefe said the only "appropriate penalty" for Knight was life imprisonment and that "parole should never be considered for her".

"She is without doubt a very dangerous person and likely, if released into the community, to commit further acts of serious violence, including even murder against those who cross her, particularly males," he said.

"A crime of the kind committed by the prisoner calls for the maximum penalty the law empowers the court to impose."

Roger Dean

In November 2011, Roger Dean, a nurse at a Quakers Hill nursing home, killed 11 people and seriously injured another eight when he used a cigarette lighter to set fire to at least two hospital beds.

It's believed Dean started the fire after he was suspected of stealing over 230 tablets from the home. He used the fire as a diversionary tactic to steal two drug registry books, which he later destroyed. In the immediate aftermath of the tragedy, Dean also appeared on TV telling journalists he tried to help residents escape the fire, but later confessed his actions to police that night.

Now serving 11 consecutive life sentences, during his trial, the now 43-year-old claimed he was "corrupted with evil thoughts," reports the ABC.

"You won't believe it, but it was like Satan saying to me that it's the right thing to do and I try very hard to not do that," he said.

"That's why I carry the bible with me and I wear my crucifix closely because I'm very afraid of these nightmares that I get a lot."

In May 2013, Dean was convicted with 11 counts of murder and sentenced to life imprisonment on each count, as well as eight counts of 'recklessly causing grievous bodily harm' and two counts of larceny. During the trial, Supreme Court Justice Megan Latham said the pain and terror experienced by the victims "must have been horrific".

"For those who were unable to move independently and who faced the prospect of being burned alive, or suffocated by smoke, a worse fate is difficult to imagine," she said.

"The family members of the victims who lingered on in hospital, only to die days or weeks later, endured the distress of watching their loved ones succumb to burns and respiratory failure."

Martin Bryant

Martin Bryant is the man responsible for the 1996 Port Arthur Massacre, which resulted in the deaths of 35 people.

His 1652 year cumulative sentence ranks as the longest sentence to be handed down in Australian history, and includes 35 life sentences, plus an additional 1,035 years, all to be served with no chance of parole.

As of 2015, Bryant has been carrying out his sentence in the maximum-security Risdon Prison near Hobart. He is now 52 years old.

If this post brings up any issues for you, or if you just feel like you need to speak to someone, please call 1800 RESPECT (1800 737 732) – the national sexual assault, domestic and family violence counselling service. It doesn’t matter where you live, they will take your call and, if need be, refer you to a service closer to home. If you think you may be experiencing depression or another mental health problem, please contact your general practitioner. If you're based in Australia, please contact Lifeline 13 11 14 for support or beyondblue 1300 22 4636.