A police officer has been spared jail for what a judge described as his terrible mistake of fatally tasering a great-grandmother with dementia.

Former senior constable Kristian James Samuel White will walk out of the NSW Supreme Court on Friday subject to strict conditions after killing 95-year-old Clare Nowland in the southern NSW town of Cooma.

The 35-year-old fired his Taser at the elderly woman after being called to the Yallambee Lodge aged-care home in the early hours of May 17, 2023.

In handing down his decision, Justice Ian Harrison found White made a “terrible mistake” but that his crime fell at the lower end of seriousness when compared to other manslaughter cases.