A police officer who Tasered a 95-year-old woman with dementia symptoms at an Australian care home has been found guilty of her manslaughter.

Kristian White, 34, used his weapon on Clare Nowland after the great-grandmother was found wandering with a small kitchen knife in the early hours of 17 May 2023.

Her death a week later caused public outcry, but White – a senior constable – argued at trial that his use of force was reasonable and proportionate to the threat.

Prosecutors, however, said Mrs Nowland – who relied on a walker to get around and weighed under 48kg (105lb) – was not a danger and that the “impatient” officer had neglected his duty of care to her.

Police and paramedics were called to Yallambee Lodge – in the town of Cooma about 114km (71 miles) south of Canberra – around 04:00 on the day of the incident, after Mrs Nowland had been seen roaming the care home with two serrated steak knives.

The trial in the New South Wales (NSW) Supreme Court heard that Mrs Nowland, while not formally diagnosed with dementia, had been displaying signs of cognitive decline in the months leading up to her death and had at times behaved aggressively towards healthcare workers.

At one point that night she had entered the room of another resident holding the knives, though he told the court he did not feel unsafe, and she had also later thrown one of the blades at a staff member.

When emergency services found Mrs Nowland, they repeatedly asked her to drop the knife in her right hand, and – using thick gloves – had tried to disarm her themselves, the court was told.

In the moments before she was hit by the Taser, footage played to the jury showed the elderly woman using her walker to slowly shuffle forward – 1m (3.3ft) over the course of a minute – before stopping and raising the blade.

White warned Mrs Nowland his weapon was aimed at her, before saying “bugger it” and firing it, while she was still 1.5m-2m away. She fell and hit her head, triggering a fatal brain bleed.

“Who could she have injured at that moment? No one,” Crown prosecutor Brett Hatfield said, summing up his case for the jury last week.

He said White had used his weapon only three minutes after finding the woman: “He was fed up, impatient, not prepared to wait any longer.”

However in a written incident report, the officer – who had been stood down from duties while facing court – said he deployed his Taser because he felt a “violent confrontation was imminent”.

In court he added that he didn’t think Mrs Nowland would be “significantly injured” and that he was “devastated” by her death.

The defence pointed to evidence from one of the paramedics and White’s police partner, who both said Mrs Nowland had made them feel scared for their safety.

“I thought that I was going to be stabbed,” Jessica Pank, also a senior constable, said.

However, both agreed they could have easily moved to safety, given Mrs Nowland’s limited mobility.

Mrs Nowland’s family, who were in court to hear the jury’s verdict, thanked prosecutors, the judge and the jury.

“The family will take some time to come to terms with the jury’s confirmation that Clare’s death at the hands of a serving NSW police officer was a criminal and unjustified act,” they said in a statement issued by a lawyer, which also asked for privacy.

NSW Police Commissioner Karen Webb on Wednesday said White’s employment was still under legal review.

She added that the force’s Taser policies and training had also been reviewed but found to be appropriate.

“The death of Clare Nowland is a terrible tragedy… this should never have happened,” she said.

White, who remains on bail, will be sentenced at a later date.