Police and ambulance both attended, with Constable White reportedly donning slash-proof gloves for the encounter.
The great-grandmother then approached the officers, using her walker while holding the serrated blade in her right hand.
A female officer accompanying White then said: “I can take it [the knife] off her,” the Telegraph reported.
After sparking the Taser failed to stop the 43kg woman and she raised her right hand, still holding the knife, White reacted.
“No, bugger it,” he allegedly said, before firing the Taser and causing the vulnerable woman to fall backwards, hitting her head and fracturing her skull.
White then said: “Got her, grab it.”
The violence against an elderly and incapacitated woman has sparked national debate about the police use of Tasers in such circumstances and the competence of aged care staff. Police are allowed to use Tasers when lives are in danger.
White was ordered on Wednesday to appear in court on July 5 on charges of recklessly causing grievous bodily harm, assault occasioning actual bodily harm, and common assault, a police statement said.
The charges are likely to be upgraded.
White has been under police internal investigation since the incident and has been suspended from duty with pay since Tuesday.
The Telegraph also reported that the female acting sergeant who attended the callout will not be charged, but may face further disciplinary action for a failure to de-escalate the situation.
Additional reporting, AP