No verdict was reached during the NSW Supreme Court trial of Senior Constable Kristian James Samuel White on Wednesday before the jury was again sent home.
The 34-year-old officer discharged his stun gun at Clare Nowland in a treatment room at Yallambee Lodge aged-care home in the southern NSW town of Cooma during the early hours of May 17, 2023.
In video footage played at his NSW Supreme Court trial, he was heard saying "nah, bugger it" before shooting the great-grandmother in the torso.
Mrs Nowland, who was holding a steak knife at the time, fell backwards and hit her head before dying a week later in hospital.
The jurors have heard eight days of evidence and submissions in the trial, including from the nursing staff, paramedics and White's police supervisor who were there at the time he fired.
They will reconvene on Monday to resume their deliberations after three hours on Wednesday and five hours on Thursday failed to produce a unanimous verdict.
Clare Nowland died in hospital a week after she was tasered. (HANDOUT/SUPPLIED)
In closing submissions, crown prosecutor Brett Hatfield SC called on jurors to find White guilty, saying his actions were "utterly unnecessary and obviously dangerous".
Mrs Nowland posed a limited threat and no one was in any imminent danger of being stabbed at the time the weapon was fired, he told the court.
However, defence counsel Troy Edwards SC argued that White's use of force was reasonable and proportionate to the danger that the 95-year-old posed while holding the knife.
It was a police officer's duty to maintain the peace and the 34-year-old senior constable did exactly that by protecting others from being injured, he told the jury.