The jail term of a single mother's murderer should be moderated to reflect her 21 crime-free years after the homicide, her lawyer has told a judge.
Isabela Carolina Camelo-Gomez, dubbed a "proven liar" by prosecutors, faced a sentence hearing on Thursday for the murder of her mother, Irene Jones, who was strangled and stabbed in her Sydney home in November 2001.
Arrested in 2019, the now-48-year-old has been in custody since May when a NSW Supreme Court jury rejected her story about a violent robbery and found her guilty of murder.
Despite continuing to deny involvement in her mother's death, Camelo-Gomez was a low risk of reoffending, had good prospects of rehabilitation and had a lesser need to be personally deterred from reoffending, her lawyer Belinda Rigg SC said on Thursday.
"(She) has, for 21 years, lived in conformity within social norms and has not offended," Ms Rigg told the NSW Supreme Court.
"The level of, what we would submit, influence upon the offender was unusual and not likely to be replicated."
At trial, the Crown said the offender had been obsessed with Carlos Camelo-Gomez, a married man her mother hated.
By killing her mother, Camelo-Gomez would remove a perceived obstacle to the relationship and inherit the victim's home, allowing her to financially support Mr Camelo-Gomez.
But crown prosecutor David Scully urged the court against trying to determine the offender's specific role in the murder plot, given the "vacuum of information".
"(It's) too much, even on the balance of probabilities, to fill in the gaps to find Carlos was the immediate instigator and it was his idea," he said.
"To then suggest Carlos Camelo-Gomez inserted himself and was the driving force, the Crown submits, would be speculation."
Mr Camelo-Gomez could not give evidence at trial as he suffered a serious brain injury after a 2013 car crash and was unable to remember prior events.
Mr Scully said there was no difficulty in the court finding the offender hadn't offended since 2001 but asked Justice Helen Wilson to consider hearsay that Camelo-Gomez was earlier violent towards her mother.
After trial, Camelo-Gomez told a forensic psychiatrist she'd been the victim of domestic violence and prison violence.
But Mr Scully said the court should reject "anything the offender says unless it is supported by objective evidence".
"The offender is - to state the obvious - a proven liar," he said.
"(She) has in the trial, the jury must have found, told an elaborate lie repeatedly over a period of time and ... the offender continues to lie."
The court also learned of the wide-ranging and lasting impacts of Ms Jones's "senseless murder" on her small, close-knit family.
The warm, engaging single mother wouldn't hurt a fly and had given her daughter so much love - often going without herself, while on a pension, relative Keith Sheldrick said.
Explaining the bloody murder scene would be imprinted on his mind forever, he said the years of speculation surrounding Ms Jones' death led to relatives' unease, nightmares and fears they'd fall victim to a random, violent robbery too.
"We will never know the full extent of what Irene suffered at the hands of the (offender)," Mr Sheldrick told the court.
"But with the little we do know, we are dismayed and disgusted for the little regard (she) showed towards her mum."
Justice Wilson will sentence Camelo-Gomez on November 16.
