There was a direct causal connection between a woman being allegedly abused as a child by a "close family member" and her eventual dark web plot to have her parents murdered, a court has heard.
"That's my opinion, your honour. I don't say that lightly," clinical psychologist Tabitha Frew said on Thursday.
The 30-year-old offender faced the ACT Supreme Court on Thursday after admitting two counts of incitement to murder, avoiding a trial that had been set down for earlier this year.
She cannot be named due to a non-publication order recently extended by 30 years.
While agreed facts have not been aired in open court, previously reported details of the case against the woman include she stood to inherit one-third of her parents' wealth if they died.
The victims' estates are said to have been worth about $8 million at the time of the crimes in 2020, when the woman was in dire financial straits.
Police said she offered a man named "Juan" $20,000 stolen from her parents to kill the pair.
However, court documents previously stated the would-be-killer working on a website called "The Sinaloa Cartel Marketplace" turned out to be a scam artist who had no intention of carrying out the fatal request.
Alleged abuse key factor in crimes, says psych
Without abuse the woman is alleged to have suffered as an eight-year-old, the psychologist told the court, she "wouldn't have committed the offences".
Ms Frew explained sexual abuse by a trusted family figure would significantly affect any child's "moral and ethical understanding of good and bad in the world".
The woman's parents have not been accused of the alleged abuse.
Defence barrister Jon White SC said: "This is not an excuse for the offending and we don't put it forward as an excuse."
Ms Frew also said if the offender did not have an undiagnosed condition of autism "she also may not have committed the offences in that way".
The woman may have been better able to communicate the alleged abuse to her parents, the court heard.
The psychologist diagnosed the murder plotter with post-traumatic stress disorder and assessed she was not faking symptoms.
Murders to 'look like accidents'
On Thursday, prosecutor Marcus Dyason said the woman told the cartel her parents' deaths "should be done as soon as possible and should be made to look like accidents".
"Financial gain was a motivation for this offending," he said.
The court heard the woman made that very assertion online, promising to pay a further sum to complete the transaction once she received her inheritance.
But Ms Frew said the woman had been clear money was not her motivation for the plot.
Ms Frew said the offender's self-reported evidence was her parents provided money "whenever she wanted it".
Asked about the woman's request for the murder to look like an accident, the psychologist responded: "That was a way to save face for them - it wouldn't seem that someone had killed them, had been out to get them."
"That it was an accident," she said.
It has been previously reported the woman transferred "Juan" more than $6000 worth of Bitcoin before ceasing contact.
In court, Ms Frew described the offender as appearing to have lost interest in following through on the contract.
But Mr Dyason alternatively proposed the woman simply did not have the financial capacity to pay the remaining amount.
The woman has previously spent more than two years in custody for her crimes.
Chief Justice Lucy McCallum reserved her sentencing decision until next month.
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