A Perth baker accused of murdering his six-month-old daughter by shaking her and throwing her onto the floor 'just snapped' because he was sleep-deprived and the teething child was restless and agitated, a trial has heard.
Isabella Sully Jean Martin's mother was working as a McDonald's manager during the day, leaving Arron Colin Martin to care for their infant at their home after he returned from early morning shifts in November 2017.
Martin's defence counsel John Rando told the Supreme Court of Western Australia on Monday his client did not intend to harm the child but 'something just happened' when she would not sleep, as he'd hoped.
'You can begin to understand the dilemma here,' Mr Rando said.
'They did the best they could. They loved the child but something was bound to happen.'
Martin was traumatised after he realised what he'd done and twice tried to end his own life before turning himself in to police, Mr Rando said.
Paramedics gave first aid to the severely injured baby at the house, then rushed her to hospital, where she died.
Arron Martin's defence counsel told the Supreme Court of WA on Monday his client did not intend to harm the child but 'something just happened' when she would not sleep, as he'd hoped.