The defence in the murder trial of David Roigard has told the jury they must prove beyond reasonable doubt that his son Aaron, is in fact dead.
Roigard is on trial for his son's murder though his body has never been found.
Defence lawyer Paul Keegan says there's no body, so there's no conclusive proof he was murdered.
"The question really is can you be sure that Aaron is dead. It's the first question that you're going to have to ask in the jury room. Bring it up, look at each other, discuss it. Is he dead?"
Keegan argued Aaron Roigard often shared his suicidal thoughts with his friends and that suicide is a likely option for his disappearance.
The defence has begun its closing argument.
"The Crown are asking you to be sure Aaron Roigard is dead without reference to his corpse, let alone how he died.
"If he had injuries, what injuries did he have? How were they caused? How were those injuries have led to his death? We know none of it here," Keegan said.
Yesterday, Crown lawyer Cherie Clarke said the only person with motivation to kill the 27-year-old was his father.
Ms Clarke says it was a premeditated and well thought out killing.
"This killing was in order to cover up well over $66,000 worth of thieving from his son over the period of 10 years," she says.