A now-quadriplegic man who stabbed his on-off girlfriend to death before severing his own spinal cord has inflicted far greater punishment on himself than any court ever could, his lawyer says.
Michael Quinn, 27, stabbed his lover Cherie Vize, 25, to death before stabbing himself on the front lawn of his family home in Wollongong in 2013.
At a sentencing hearing in the NSW Supreme Court on Friday, Quinn's barrister Janet Manuell, SC, said her client, who is a quadriplegic from his self-inflicted wounds, "is and will be for the rest of his life imprisoned within his body".
"These injuries were catastrophic in every respect. They have ruined Mr Quinn's life and, to add further seriousness to the catastrophic nature of the injuries, Mr Quinn also has identifiable, recognisable mental illnesses," Ms Manuell said.
"The fact of his limitations in terms of intellectual stimulation within both his body and his mind and within the strictures of justice health impose a burden on him that must be getting close to intolerable."
In a letter dictated to his counsellor and submitted during the hearing, Quinn said there were "very few waking moments" when he did not wish he could change what had happened.
"I have nowhere in me to put this. I don't know how to process it, I think that's because there is no way to process such an irredeemable offence, of taking a life," the letter stated.
"I have caused great pain at the very heart of those I love; nothing can ever be the same again. I have changed the course of many lives; I have not been a positive contribution to others in this lifetime of mine."
Quinn pleaded not guilty to the murder, and testified that he had accidentally stabbed Ms Vize when he was trying to kill himself and she intervened.
His defence team argued that, even if he had deliberately killed Ms Vize, his criminal culpability should be reduced from murder to manslaughter because he was substantially impaired by an abnormality of mind at the time.
The Crown's case was that an obsessive Quinn was in a jealous rage when he stabbed Ms Vize shortly after discovering she had started a new relationship.
He had contacted Ms Vize's mobile 227 times in the 11 days before her death, while she had only contacted his nine times during the same period.
Delivering his verdict earlier this year, Justice Robert Beech-Jones said Quinn had made claims during his trial that were "completely implausible" and "untruthful".
In a victim impact statement tendered during the sentencing hearing, Ms Vize's mother Evansueda Vize said it was unfortunate her daughter, a budding artist, had ever met Quinn.
"We opened our home to him and treated him like a part of our family because that was what Cherie wanted," Mrs Vize wrote in the statement.
"When she was taken away from us in these horrendous circumstances, our whole lives were shattered and our future was destroyed."
Crown prosecutor Mark Hobart, SC, told the hearing that Quinn had been charged with four offences since he had been in custody. They included two counts of intimidation and a count each of damaging and destroying property and committing an act of indecency.
"He has lied in so many different ways in this case," Mr Hobart said.
Quinn will be sentenced next month.