One of the three children accusing their father of sexual abuse had "powerful motives for lying," a defence barrister has told a jury.
The trial of the 53-year-old father, who cannot be named to protect the identity of his children, continued in the ACT Supreme Court on Thursday, August 27.
He has pleaded not guilty to 10 charges, including committing an act of indecency without consent, sexual intercourse with a child under 10 and making a threat to kill.
It is alleged the father committed a series of sexual assaults against his son and two daughters over the span of several years.
He is accused of indecently assaulting his son in a kitchen, raping him months later, and, on a separate occasion, holding a hunting knife to his throat while threatening to kill him.
The father also allegedly indecently assaulted his two daughters in a car on different occasions when they were under the ages of 14 and 16.
He is further accused of sexually assaulting the second daughter in a bedroom and threatening to hurt her if she spoke out.
During closing submissions on Thursday, defence barrister James Walker said this trial was about "three children who have made allegations that are not supported by any objective evidence".
"It is about allegations made to police by complainants who hate or despise [their father]," Mr Walker said.
"It is about allegations that have evolved over time... and, for one of the complainants, we know are lies because he told us so."
Mr Walker claimed the three children discussed the allegations together in a backyard before going to police.
He said the children's allegations had escalated only after that backyard discussion, arguing their memory of events may have changed as a result.
"You would be very concerned that the memories have been less and less accurate over time, if they had been accurate to begin with," Mr Walker told the jury.
He pointed to the father's police interview, where the accused called the claims "bullshit" and said the allegations "made him sick".
He also noted that when the son was 16, he told the court under oath that the allegations of sexual abuse and threats to kill were not true.
Mr Walker said the boy had motives for lying, pointing to testimony that his father used to "slap him around" and swear at him. He noted the child had also openly admitted he "despised" his father.
While the prosecution may try to excuse the boy's courtroom denials, Mr Walker said, they are ultimately "the words [the boy] used and we are stuck with them".
The barrister asked the jury to consider that if his allegations were fabricated, the two girls may have lied too, but hadn't admitted it yet.
In her closing address, Crown prosecutor Amanda Mifsud said the children gave honest statements to police and argued the father's alleged actions "were not accidental".
"It was deliberate conduct that occurred over years," she said.
Ms Mifsud said the children could have "bolstered" their evidence to make the allegations more damning, but instead acknowledged when they did not remember exact details.
She also argued there was no "cover-up" of the discussions between the children about their allegations, pointing out that all three spoke openly about the backyard conversation.
Addressing the moment in court when the boy agreed with defence questions that the sexual assault allegations were false, Ms Mifsud suggested the child had misunderstood what was being asked.
She asked the jury to consider that the boy was "frustrated" and simply agreeing with the defence "to get [his evidence] over and done with", urging them to set his courtroom testimony "to one side" in favour of his original police interview.
The trial before Justice Belinda Baker continues.
