There is no question Natasha Beth Darcy told "lots and lots of lies" to police following the death of her partner, grazier Mathew Dunbar, her defence barrister has told a jury.
Ms Darcy is accused of killing Mr Dunbar by sedating him with a cocktail of drugs – blended in a NutriBullet – before gassing him on his sheep property 'Pandora' at Walcha near Tamworth in August 2017.
The alleged murder took place on the property Ms Darcy had been made the sole beneficiary of, after months of asking Mr Dunbar to change his will.
READ MORE: Murder accused Natasha Darcy 'searched for hundreds of ways to kill' farmer Matthew Dunbar
In her closing arguments in the NSW Supreme Court today, Ms Darcy's barrister Janet Manuell SC told the jury her client had made things worse for herself by telling repeated lies.
"Think about it; one of the problems with lying is that once you've told one lie you've got to keep telling a whole lot more lies if you're going to keep up with the original lie," Ms Manuell said without elaborating on what the 'original lie' was.
"Some people fess up to the original lie – some people don't – and they just make things worse and worse and worse.
"That's what's happened here – Ms Darcy has made things worse and worse for herself by the repeated lies she's told."
READ MORE: Widow offered friend $20,000 to make false statement ahead of murder trial of farmer Mathew Dunbar, court told
Ms Manuell then asked the jury to ask themselves why people lie.
"They might think they've been unjustly accused… they might think nobody is going to believe them."
Ms Manuell told the jury that they could not find Ms Darcy guilty of murder if they thought there was a "reasonable possibility" Mr Dunbar had suicided.
"If you think there is a reasonable possibility that Mr Dunbar died by his own hand you must acquit the accused," Ms Manuell said.
It is the Crown case Ms Darcy was aware of Mr Dunbar's history of depression and that he'd previously threatened to take his own life.
"This was known to the accused and she exploited this and killed him in the manner she did to make it look like a suicide," Mr Hatfield in his opening address.
READ MORE: Grazier bought helium allegedly used to kill him
Ms Manuell told the jury it was up to the prosecution to exclude the possibility of suicide and argued there were 12 reasons why that could not be done:
- Matthew Dunbar's history of depression
- Reported suicidal ideations in the past
- A search on the family computer for various methods of suicide and "how to stop suicidal thoughts' (which the prosecution argues Ms Darcy carried out)
- The Crown cannot exclude that Mr Dunbar "was an active and knowing participant" in obtaining a cylinder of helium (which the trial has heard, caused his death)
- The implausibility of Ms Darcy watching a video about a suicide method which the Crown alleges she copied to later kill Mr Dunbar with, while she was seated next to him at a Tamworth cafe on the final day of his life
- How the video was accessed on Ms Darcy's phone for one minute and 48 seconds at the cafe at a time when the defence argues Mr Dunbar had not "accessed" his phone, according to timestamps
- Implausibility of Ms Darcy watching the video after the cylinder of helium had been purchased
- The period of time Mr Dunbar had to make preparations for the way in which he later died when Ms Darcy and her children took their cat to the vet on the afternoon of August 1. (Mr Dunbar was found dead in the early hours of August 2)
- The difficulty Ms Darcy would have had in removing an item from the helium cylinder to enable gas to be dispersed
- Presence of Mr Dunbar's DNA on the shower hose which had been connected to the helium cylinder
- Presence of Mr Dunbar's DNA on an elastic band
- The cocktail of drugs blended in a NutriBullet which Mr Dunbar consumed: "Drinking a drink which must have been thick with pulverized tablets…we know it had all those crunchy bits in it".
The trial continues before Justice Julia Lonergan.
Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14. National Domestic Violence Service: 1800 RESPECT (1800 737 732). If you are in immediate danger call Triple Zero (000).
